In the morning, it awakes full of ambition, with a courageous heart and sharp teeth, so it can take everything it desires. At noon, it rests on its treasures, at the height of its strength and wisdom, still brave enough to defend what it has acquired. At sunset, its teeth are dull, it forgets its courage, and it squanders its hard-won riches for fleeting moments of pleasure. When night falls, it succumbs to sickness, writhing in agony as it rots alive. But if no predator or scavenger consumes it in the dark, at dawn it rises again, rejuvenated and strong. What creature is this?
Let's explain. The "Imperial Cycle" of history is a model that is put forth to try and explain the history of empires or other great states. It should be noted that this model is highly simplified and somewhat hidebound so that it can't fully fit every empire that has existed, but it is still an elegant and relatively accurate model, and highly influential in culture (especially Chinese and other culture in the Sinosphere). According to the theory, the History of every empire, real life or fictional, can be divided in four parts:
Phase One: Expansion
During this phase the Empire is still young and rising, many of its rulers are ambitious, and those with money often give them the loans they need to conquer their enemies. These days see the Empire established by military expansion, and also the most betrayals and civil wars, as many great leaders may turn against each other in their desire to take the throne for themselves. The Empire racks up massive debts from all this warfare, and its economy is likely totally devastated, but with its borders secure it'll probably be able to pay off its debts over the next few generations.
The ruler of this era is The Conqueror and Founder of the Kingdom. Serving him are The Good Chancellor or Evil Chancellor (depending on moral allegiance usually), fathers to their men, and just heroes of legend and lore. Opposing him are Feudal Overlords clinging to their old crumbling castles, warlords and barbarian chiefs, for whom Authority Equals Asskicking and Might Makes Right, opposing would-be empires and claimants to be met in climatic struggle, and hardline devotees of a previous empire, who want to preserve what little is left of it. This era ends when there is either nothing left to conquer worth conquering, or when everyone is just so indebted or exhausted that there is literally no money left to be loaned or taxed and The Empire can't afford to fight anymore. With long awaited peace the second phase begins.
Phase Two: Stabilization
In this phase the conquerors die off and are replaced by administrators who help estabilish a system of rules and institutions used to manage their empire, overseeing an era of economic & demographic recovery and growth and gradually paying off the still-massive debts of their ancestors. It may also involve a purge of hotheads who still think in terms of brute force, which is a significant source of internal conflict during this era. While not as aggressive as their precursors, rulers of this phase know war very well, having learned from conqueror's experience. Conquest may still occur, but the empire is more focused on protecting what they already have and use it to become stronger in cultural, administrational and economical sense, becoming a Hegemonic Empire.
The ruler of this era can be a Reasonable Authority Figure, though they can also be a Totalitarian Utilitarian control freak. Badass Bureaucrats, Honest Corporate Executives and, quite possibly, some Secret Police support them.
Phase Three: The Decay
After the administrators' work is done, with debt down to manageable levels and no serious outside threats remaining, comes a time of economic growth and real prosperity. This may or may not involved a population high as well, which is a problem because agriculture can only support so many people in the long-term - meaning that many people will starve and die in times of famine until the population falls to sustainable levels again. The biggest problem facing The Empire is that more and more wealth and power is concentrated in private hands and not those of the state - the nobles and merchants become more and more strong and big, and the central government has more and more trouble getting local and regional governments to cooperate. The increasingly delicate balance of power is easily disrupted if just one Spoiled Brat inherits the throne and lets this weakening of the state happen. Even if there aren't any, the new generations of rulers take little pride from the administrators and think of their conquerors' heritage instead, often wasting state money on expensive military campaigns to expand the Empire just for the sake of conquest. They tend to spend their life on never-ending consumerism or hedonism, wasting what previous generations left for them instead of trying to secure or multiply it through 'boring' things like building infrastructure, re-organising the taxation system, or establishing new trade missions.
The ruler of this era can be The Caligula, a Royal Brat, an Adipose Rex, or a possible well-meaning but inept ruler, Unfit for Greatness, who will only make things worse with their reforms; helping (or hindering) him are a cabal of obstructive and corrupt bureaucrats and the whole Deadly Decadent Court, some of whom are on the payroll of a Corrupt Corporate Executive or two. Such an empire can already be called vestigial; it may not yet suffer loss of territories, but its influence is waning. The fate of Empire that enters this phase is to fall; the point of no return is already past, and no matter how gilded is the empire's facade, its structure is rotting, and the only way to stop it is a top-down revolution, that is, to tear everything down and rebuild from scratch (think Meiji or Peter the Great).
Phase Four: The Long Night
The Empire exists in name only at this stage. It is now a failed state, a gray zone of squabbling independent shards or sub-factions. The dissipation of The Empire's power to rich and strong and big individuals (oligarchs) is complete, with many families and even regions now only paying lip-service to The Empire and its supposed rulers. The Empire's fiscal situation is a mess because very little money will be coming in thanks to disloyalty and corruption, even though the state's debts haven't gone away - the debt might even be growing. This will be the case regardless of whether The Empire itself is still experiencing economic growth or not, but it's very likely that The Empire is also experiencing economic contraction due to the increasing concentration of wealth in the hands of fewer and fewer peoplenote . Long-term population decline is also likely, mostly due to the unsustainability of the previous population high - i.e. some people will starve because the total population's food requirements exceed total sustainable food production - but also due to banditry, civil disorder, and even Civil War.
Only a small part of the former empire's territories, half or less, give money to or actually take orders from the former capital; this is called a rump state, or a late, actually Vestigial Empire, where utter ignoramuses try to simulate the old Empire in a Cargo Cult-ish fashion, dressing in the robes of long-dead emperors and spouting bombastic orders no one actually listens to. The decadence of the old Empire is now concentrated around a few select oligarchs and their surroundings, possibly a rich city or two, and the rest of the populace is struggling hard to get something to eat. The majestic and titanic monuments of the previous imperial eras turn into ruins or are resettled by bandit gangs, marauders or folks more sinister still.
The ruler of this era is Authority in Name Only with a 0% Approval Rating, a Small Name, Big Ego pompous gasbag of a dictator or an outright Empty Shell who has lost all will and cognition due to Despair Event Horizon, a Fisher Kingdom effect or just plain senility and/or alcoholism, practicing Head-in-the-Sand Management. A Vast Bureaucracy may form, stifling any and every positive idea and pilfering away budgets. The peripheries, which the rump state no longer controls, are home to Feudal Overlords clinging to their old crumbling castles, warlords and barbarian chiefs, for whom Authority Equals Asskicking and Might Makes Right, and yet more Small Name, Big Ego dictators, who are pleasantly surprised that they don't have to kowtow to anyone any longer. However, in one or more sub-factions, intelligent leaders may arise and plan a new Empire; a new Expansion begins when one of them emerges openly, unambiguously triumphant.
Adjacent empires can see the rotting carcass of the empire ripe for plundering; they may directly intervene, send troops and partition the dead empire into colonial or semi-colonial pieces, or they can use hegemonism and make the petty states of the ex-empire their puppets.
Eventually, the Long Night ends with either total disappearance of the empire, its shards growing from petty and self-proclaimed to true distinct nations, or fading culturally and becoming just governorates of neighboring nations, or a climactic Civil War in which it is reforged in fire and steel and re-enters Phase One.
In fiction, the borders between phases are mostly clear, but in Real Life it wasn't always so clear - neither Caligula nor Nero brought the Decay stage upon the Roman Empire, because when the empire is mighty, the occasional tyrant doesn't hurt it much. It wasn't also uncommon to have rulers more fit for the second phase to appear in the first or third, trying to stabilize the situation. They can even pop up in the fourth phase, bringing the rump state back from failed to just decayed. However, it's usually impossible to restore the former regime to its full glory without serious reformsnote ; even if such a restoration happens it usually either comes back wrong (and is already in the decay phase), or is too fundamentally different to be considered the same Empire (such as being brought back to the expansion or stabilization phase but speaking a different language, functioning with a different form of government and a different economic model, practicing a different religion with different morals, and sometimes ruling completely different territories). To truly restart the cycle, new ideas and institutions are required.
Supertrope to Standard Sci-Fi History.
- Noted as a recurring theme in Legend of Galactic Heroes. After achieving space travel, humanity entered a golden age of expansion and prosperity, but after some period of this, they begin to stagnate, and fall into Phase 3, and Phase 4 soon after that. Eventually, the first Emperor of the Galactic Empire reunites humanity under his rule, and begins a rather dark Phase 1. However, by the time the story proper starts , the Empire has fallen into Phase 3, teetering on the brink of Phase 4, with the Deadly Decadent Court slowly tearing it apart at the seams. However, when Reinhard takes control, he pulls it all the way back to Phase 1, and by his death, it seems to be entering Phase 2.
- Even the Free Planets Alliance is not immune to this trope; it was at one point it could actually hold its own agains the Empire, and potentially defeat it. However, it became complacent and began to descend into corruption, leaving it ill equipped to deal with the Empire when Reinhard takes the reigns of power.
- In Code Geass, the Holy Britannian Empire is somehow simultaneously in both Phase 1 and 3, being both at a point of unrivaled power and expansion, while being corrupt to its core at the same time. The Emperor all but invokes this trope as a way of weeding out the weak in the world, and seems intent on skipping Phase 2 altogether.
- The Balt-Rhein Empire in Shoukoku no Altair (despite outwardly appearing to be Phase 1) is indicated to be in Phase 3; its refusal to engage in trade, and its uncompromising, expansionistic policies have made it a pariah on the political stage, and left its entire infrastructure based on war. Eventually it enters Phase 4, with half of its territory being lost, its treasury being all but empty, and most of its military destroyed.
- Türkiye is suggested by a few characters to be about to enter Phase 1, with Balt-Rhein being the only thing in its way.
- The Shi'Ar Empire from X-Men was in the Phase 1 under the rule of D'Ken. Under Lilandra it set up on Phase 2 but viarous crisises (many of which involved X-Men) threw it into phase 3, leading to secret conspiracy trying to re-estabilish D'Ken as a ruller, only for Vulcan to take it over, leading to new Phase 1, which lead to War of Kings. After their defeat Shi'Ar are now in another Phase 2.
- In Star Wars, the Galactic Republic is in decline at the start of the Episode I, but Emperor Palpatine, rather than squandering it, restores it to expansion, but at the cost of turning it into, well, The Empire. By Episode IV, it is at the end of the stabilization phase. As Leia had predicted, the decline of his empire is rapid: "The more you tighten your grip, Tarkin, the more star systems will slip through your fingers." After Endor, the Long Night for the Empire takes place as The Remnant is forced to withdraw to the Unknown Regions even as the New Republic enters expansion. Roles have flipped by Episode VII. The New Republic thinks they are in stabilization, but are in fact in decay. The Empire's successor state, the First Order, has entered expansion thanks to a massive military buildup conducted in defiance of treaties with the complacent New Republic.
- In The Black Company, Lady's Empire is clearly Phase 1, however it later moves to the Phase 2. This trope is even lampshaded in The Silver Spike.
- The CoDominium was an alliance between the United States of America and the Soviet Union that took over earth and colonized most of known space, it collapsed when the founding states finally sterilized earth in a nuclear war. Then the former American colony Sparta decided that humanity must be united under a single rule and conquered the other surviving colonies forming the Empire of Man, some centuries later this Empire falls thanks to a rebellion by the Sauron supermen. After a few more centuries of dark age a Second Empire emerges.
- In The Mote in God's Eye the Second Empire contacts an alien race that due to their ridiculous breeding rate experiences the empire cycle frequently, so much so that they've depleted their system's supply of fissionable material. However they're restricted to one system because the only Alderson Point in their system of origin leads into a red supergiant.
- In Steven Brust's Dragaera series, the empire (called, naturally, "The Empire") goes through "the cycle," a series of rulers based on their clan (each ruling several hundred years). It has gone through several cycles, always starting with the ascendant Phoenix, through all 17 clans, and ends with a decadent Phoenix. The cycle is then repeated. Recently the cycle was broken by a catastrophic event, but has started turning again.
- Barryar in the Vorkosigan Saga is in phase 2. It is becoming more cultured and less violent and has more or less halted expansion but it still retains memories of old ways. The present Emperor is a Reasonable Authority Figure who was apprenticed by one of Barryars greatest statesmen in history. Ezar's last order is also an example of purging hotheads.
- More precisely, Barrayar was in a Long Night period (the Time of Isolation) until it was united by Emperor Dorca the Just. This followed with the Cetagandian invasion and then a civil war to overthrow Mad Yuri. After that was a period of expansion and consolidation of Ezar's reign followed by Aral's regency and then the reign of Gregor. Dorca and Ezar were ruthless but competent rulers who were able to lay the foundations for a possible system by ability at head-cracking and were thus appreciated by people who had known only chaos. Gregor is a more civilized ruler for a more civilized time and is able to live like a sedate gentleman. Aral was an old-school aristocrat who could keep a lid on the vor aristocracy and keep foreign powers away while slowly evolving Barrayar into a calmer system. His term was the bridge between phase 1 and phase 2. Like Dorca and Ezar he cracks heads occasionally and is good at it but Aral also manages the feat of slowly teaching Barryarans to live without head-cracking. He retains a little of the temperment of the old days and a little of the new.
- Fredric Brown's Letter to a Phoenix, where a 180 000 year old man claims he saw Humanity bomb itself into the stone age six times already.
- In The Republic Of Trees it is discussed as "historical gravity" - everything that rises, from empires to revolutions must fall one day. And yet people keep trying, hoping that they will be the first to get lucky.
- Has occurred several time in the history of the word in A Song of Ice and Fire. The Valyrian Freehold fell during the "Doom of Valyria" and before that the Ghiscari Empire conquered much of the continent before they were displaced by the Valyrians. And then the Targaryens, one of the few survivors of Valyria, went on to conquer Westeros and found their own Empire, the Seven Kingdoms, and the story starts 15 years after the last Targaryen king was dethroned in Robert's Rebellion, and while the kingdom survived the initial aftermath of the war events within the series kickstart the fracturing of the state into its own regions again.
- The cycle of the Targaryen dynasty can be roughly seen as follows: the Expansion period begins with the reign of Aegon the Conqueror and ends with the death of Maegor the Cruel, as most of Westeros (with the exception of Dorne) was brought under Targaryen rule. The Stabilisation period consists of the reigns of King Jahaerys "The Old King" and King Viserys I, as it was during this period that Targaryen power and prestige was at its apex. Immediately following is a long, protracted period of Decay that began with the death of Viserys I and the Dance of the Dragons. This conflict sealed the doom of the primary source of Targaryen power, the dragons, and destroyed almost all of the Targaryen family. This period of decay was, like the Western Roman Empire, filled with pretender rebellions and kings who were able to temporarily slow the decay (such as Daeron II"The Good"), as well as kings whose overambition or foolishness led to massive structural problems of the kingdom, such as Daeron I "The Young Dragon" and Aegon IV "The Unworthy". It's difficult to say exactly where the Decay period ended and the Long Night began, but a safe guess would be the reign of Jahaerys II, who neglected the diplomatic approach of his father Aegon V in favor of traditional Targaryen marriage. This culminated in Aerys II, whose madness alienated almost all of his vassals and caused the overthrow of the Targaryen dynasty itself. It should be noted that the delineation between the "Expansion / Stabilization" and "Decay / Long Night" can also be seen as the period where the Targaryens' incestuous marriages began to catch up with them.
- The Confederacy of Suns in The History of the Galaxy is more The Federation than The Empire, but it fits the cycle. It arose shortly after the Galactic Wars as a means to keep the peace between various colonies. However, the setup was inherently unequal, with the five Core colonies being given more political weight than the Border worlds that vastly outnumbered them. The creation did bring stability for a few centuries. However, the lack of external enemies beyond occasional Space Pirates and rogue Mega-Corps coupled with the dissatisfaction of the Border worlds and the increasing corruption led to the Confederacy's slow decay until its dissolution. A few decades later, a previously-unknown alien foe deals a crippling blow to the colonies and is only repelled by a few brave individuals. This forces the colonies to reconsider and re-form the Confederacy, although each member world is now equal. Later novels show that the Confederacy may seem stable, it now faces numerous threats both from newly-discovered alien foes and strong and big internal elements, and it hasn't even been that long since the new Confederacy was founded.
- The League from The Stainless Steel Rat is an attempt to reassemble all the Lost Colonies of an Empire which fell about a thousand years ago, and is still far from done. In The Stainless Steel Rat Wants You, we see an Alternate Timeline where this Empire (or a similar one) apparently never fell due to the need to fight an alien invasion.
- Robert E. Howard detailed such a cycle for the Hyborian nations from Conan the Barbarian in his essay "The Hyborian Age". Aquilonia is given particular focus; it seems to be sliding into the decay phase, until Conan takes over and restarts the cycle, which allows it to last another five hundred years.
- The Bright Empire of Melnibone from The Elric Saga is in the midst of its Long Night by the series' beginning. The Empire is mostly restricted to Melnibone itself, mainly within the city of Imrryr, but only recently have the humans felt bold enough to attempt an invasion, which fails catastrophically. While Elric, the current emperor, could restore some of their strength if he wished to, he ultimately chooses to lead a second human raid on Imrryr, which destroys the Empire for good.
- This is the basis of The Foundation Trilogy. Seldon's psychohistory recognizes that the Galactic Empire is quite far into the Decay phase, or even already in the beginnings of the Long Night, which will result in thirty thousand years of anarchy before a new empire arises. He establishes the Foundation to minimize the coming dark age and usher in the Second Empire in "only" a thousand years.
- Andromeda takes place in the Interregnum of the Systems Commonwealth, with the titular ship's crew trying to establish a new Commonwealth.
- They manage to restore it in a later season, but only about 50 systems to start, while the original Commonwealth stretched to three galaxies. In fact, the Commonwealth itself was originally the expansionist Vedran Empire. It's only when it became too large to effectively maintain control via imperial means that they agreed to form the Commonwealth with the Vedran Empress being relegated to be merely the Head of State, while the government is actually run by the Triumvirs and a tri-cameral parliament mostly composed of non-Vedrans. The new Commonwealth is corrupt with a number of its members eventually betraying them all over again.
- The Korean drama Emperor Wang Guhn was type 3 and type 1. Taking place in the 9th century AD, it shows the decline & fall of Silla and the rise of Koguryo (modern day Korea).
- The main powers of Babylon 5:
- In theory, Earth Alliance and the Narn Regime are in a phase of expansion. In practice, however, the Narn are bottled up between powers that can hold their own against them (Earth Alliance and the League of Non-Aligned Worlds) or crush them in a matter of weeks and cannot expand anymore. As for Earth Alliance, while they're currently recovering from the Earth-Minbari War and thus don't have the means to expand with force, they still manage to expand by colonizing uninhabitated systems (how they quickly expanded in a power big enough for the Centauri to not easily swallow them up) and diplomacy (and in fact an episode is centered about troops going to help Earth's newest protectorate passing through the titular station);
- The Minbari are in a phase of decay for most of the series, and actually enter a very brief interregnum before Delenn manage to re-stabilize them and initiate a new expansion phase (at least population-wise, as it's implied their terminal population decay is reversed);
- The Centauri are in their Long Night (in fact both the Narn Regime and part of the League used to be Centauri territory), but, thanks to technological development, are strong and big enough they could easily reconquer all the lost worlds if they only wanted... And in fact they proceed to do just that: when the Shadows' machinations finally ignite a war with the Narn Regime, the Centauri discover their so-called nemesis was unable to resist their overwhelming might, and they later start a war on the League and are winning on all fronts (all twelve of them) before Londo put them back in a phase of stabilization. The Shadow War and the following events bring them back in a phase of decay, but the novels show them returning to stabilization and possibly a new expansion;
- The Lost Tales show that the Centauri, if left unchecked, will return to their former might in only a few decades and will be stronger than the Earth Alliance.
- The League is mostly in a phase of stabilization, but their most stromg and big members, the Drazi, are pushing for their own expansion;
- And the whole setting is actually in the Long Night between the rule of the First Ones and the rise of a race capable of living outside their tutelage. This is made more complicated due the First Ones being either expanding or stabilized, with most of them having left the galaxy and the remaining ones trying to teach to the Younger Races
- Star Trek: The United Federation of Planets goes through the cycle during numerous series of the Franchise. In the 23rd and possibly the early 24th Century it is in its expansion phase and pretty much ever expanding untill it is the biggest power in the Alpha and Beta Quadrant. In the 24th Century, especially during the time Jean Luc Picard is active as a Captain, and the Major Power in the Alpha Quadrant, beeing able to fight a war against the Cardassians without ever switching to "war mode", possibly going without really beeing threatened for decades untill the Borg and later the Dominion appear. While the War against the Dominion was devastating for the Federation and could only be won with the help of the Klingons and Romulans, by the time of Star Trek Picard has recovered again, even if it has withdrawn somewhat, which is a point where it could either slip into decay or recover and stay in Stability, with the latter seeming a little more likely. Judging from the trailers for Star Trek Discovery Season 3, in the 33rd century the Federation is in the long night, with only a rump state remaining.
- In The Bible, Israel goes through this:
- Expansion: Joshua
- During the 300+ years long period of the Judges it waffles between stability and decay.
- Expansion: Kings Saul and David
- Stability: King Solomon's reign of peace brings the nation to its highest point but also sows the seeds of its destruction
- Decay: King Rehoboam's actions lead to the kingdom being split and starts a 390 year long period of decay
- Long Night: destruction of Israel/Samaria by the Assyrians and Judah by the Babylonians, ending the 470 year long Davidic dynasty
- Invoked in The BBC's 1980 sci-fi drama Earthsearch. The two power-hungry Angel computers who control the Challenger plan to return when the civilisation that created their ten-Mile-Long Ship that can travel at near-light speed has collapsed into a dark age, enabling them to Take Over the World because they'll be regarded as gods. Unfortunately due to an error in Time Dilation they return to find that a million years have passed and the humans have evolved the technology to move their planet to another solar system! All that is left is the Solaric Empire — a Vestigial Empire that's forgotten its own origins. However in Season 2 the Angels finally locate the Earth and find it has indeed collapsed into a primitive state.
- Ars Magica uses this model on a smaller scale for its covenants (small organisations of wizards working together, and living in the same location); it names the phases after the seasons. In the Expansion phase ("Spring") the covenant is established by weak magi, and focusses on getting the resources it'll need to survive; by the Long Night phase ("Winter") it's falling apart, and empty except for a few old, peculiar and strong and big magi who haven't noticed that everyone else has gone.
- BattleTech is set during Long Night following the demise of the Star League. Each of the five Inner Sphere Successor States and the eleven Crusader Clans have ambitions of becoming the next Empire - though ComStar makes the most successful and destructive attempt.
- Fading Suns has gone through two corporatocratic Republics and is slowly emerging from a dark age as a feudal Empire.
- The Third Imperium in the default setting of Traveller is in phase 2. The Vilani Imperium in Intersteller Wars is in phase three and the Terrans in phase 1; the Vilani Imperium arose thousands of years ago at the dawn of Terran civilization and founded an Intersteller Empire so large that it could withstand decay simply through its size and had been a Vestigial Empire for centuries when the Terrans discovered it. However, the Terran-based Second Imperium never stabilizes and quickly succumbs to phase 4, suffering The Long Night, because it inherited all problems of the Vilani Imperium. In the Megatraveller timeline the Third Imperium lasts about 1120 years before Emperor Strephon is assassinated and in the resulting Succession Crisis a weaponized Contagious A.I. tears apart not only the Imperium but the neighboring alien empires as well.
- Valence has a somewhat screwy Cycle of Empires that generally goes from strength to strength. The Innueliting Empire spent millions of years in the Stabilization phase before being usurped by the Budetug Empire, which grew to dominate the galaxy while a rump Innuel Empire declined into cheerful obsolescence. Then the Budetug got knocked over by the Caractingessen a million years later, and the Hallans took over the Caractingessen Empire just as fluidly when the Emperor died. The Hallans completely failed to run anything, though, and their Empire collapsed from neglect, creating the first Long Night, which lasted for a few centuries before the humans launched a crusade to reunite the galaxy. When Earth fell, the Empire went with it (no "decay" phase) and plunged headlong into the current Long Night. Incidentally, the first two Empires are still around as the Innueliting Empire and the Budetug Core Worlds, while the four biggest powers in the galaxy are all shards of the Human Empire; three are corporate dominions while the fourth is the Coalition, a nation-state.
- Warhammer 40,000:
- The Eldar's ancient empire was born in the aftermath of the near-mythic War in Heaven, when the Old Ones uplifted races like the Eldar to help fight the Necrons and C'Tan. With the Necrons defeated and the Old Ones exhausted in their victory, the Eldar were able to spread across and dominate the galaxy before humanity had discovered fire. The Eldar boast that "The stars themselves once lived and died at our command," and at their empire's height its citizens wanted for nothing and had constructs to toil on their behalf, so all they had to concern themselves with was finding entertainment. Then they hit the Decay Phase, hard - the highly-psychic Eldar grew so jaded and decadent that they began to embrace all matter of perversions, preying upon each other and forming cults of excess, until their society began to break down and the Warp grew turbulent from the dark energy fomenting in it. The end result of literally millennia of debauchery was the creation of Slaanesh, the Chaos God of sickening hedonism and sadistic pleasure, whose psychic birth cry consumed the souls of billions of Eldar, slew most of their pantheon, and tore the heart out of their empire, leaving behind the Eye of Terror as a hideous afterbirth. Some lucky Eldar saw this coming and survived the Fall by fleeing to their empire's hinterlands, either on Exodite colonies or in starfaring Craftworlds, while the Dark Elder continue their murderous, decadent ways safe in the heart of the Webway. Regardless, the Eldar are in their Long Night, staving off extinction while younger, lesser races have inherited the galaxy, and only the most ambitious and/or foolhardy speak of somehow restoring their lost glory. Yet there is still a glimmer of hope in the form of the prophecy of Ynnead, the God of the Dead, who will someday awaken, defeat Slaanesh, and reunite the sundered Eldar kindreds.
- Somewhere between the Fifteenth and Twenty-Fifth Millennia, humanity entered what is alternately known as the Golden Age and the Dark Age of Technology (mankind was at its technological peak but in a spiritual dark age, by contemporary Imperial standards). While the Eldar stagnated and lost themselves in their amusements, humanity mastered Warp Drive and was able to turn its scattered colonies into a galactic civilization. They produced wonders like the Standard Template Construct system, complex analytic programs that contained the entirety of humanity's technological knowledge, which Constructor units could use to create any needed device using whatever materials were available. Then the Decay phase started with the triple whammy of increasing mutation and the manifestation of psychic powers among humanity, the rebellion of the "Men of Iron," and Warp Storms caused by the Eldar's decadence making interstellar travel impossible. Humanity's galactic civilization collapsed into the Age of Strife, Terra descended into barbarism after losing the support of its colonies, and most of mankind's technological knowledge was lost forever, with only scraps of STC hard copies surviving to guide future generations. Ironically, the Fall of the Eldar paved the way for humanity's recovery, by removing the Eldar Empire as a rival power and dispelling the Warp Storms plaguing the galaxy with Slaanesh's calamitous birth, allowing for (relatively) safe Warp travel to resume.
- At the end of the Age of Strife, around the Thirtieth Millennium, the being known only as the Emperor succeeded in winning the Terran Unification Wars, formed an alliance with the Mechanicum of Mars, and proceeded to launch a Great Crusade to reunite the galaxy at the fore of twenty legions of Space Marines, each led by one of the Emperor's clone-sons. But just when the galaxy seemed conquered and the Imperium of Man was ready to enter its Stabilization phase, the Horus Heresy struck - the Emperor's most trusted son fell to Chaos and led half of his brothers in a civil war. The tratiors proceeded to ravage the empire they helped build, laid siege to Holy Terra, and mortally-wounded the Emperor, but were ultimately defeated and driven into the Eye of Terror. For a brief time the Imperium tried to recover, only to be hit by the War of the Beast, the resurgent Traitor Legions' first Black Crusade, and so forth. For most of its existence, and despite periods of resurgence, the Imperium has been trapped in a long, slow decay, where internal divisions and external threats are only exacerbated by its inefficient government and dwindling technical knowledge, so that only its sheer size and the tenacity of its armies have prevented it from collapsing entirely (which would probably mean humanity's extinction). As of the Gathering Storm, the Imperium's fate is uncertain - it has been split apart so that half of the galaxy is out of contact with Terra, but Roboute Guilliman has returned to reform and revitalize its administration and military, so it has at least a chance of survival.
- The Tau have a Rising Empire on the eastern galactic fringe, and went through a rapid Expansion phase thanks to their advanced technology. Then, shortly before the setting's "present," they encountered the Imperium and got hit with the Damocles Gulf Crusade, which ground to a bloody stalemate until other, more urgent threats like the Tyranids made the Imperium agree to an uneasy ceasefire. Now the Tau leadership has a better idea of just how small their empire actually is compared to the Imperium, and know to time future expansion carefully. For their part, the Imperium would dearly like to exterminate the Tau, but committing the forces to do so would critically weaken its many other warfronts, and for the moment the Tau are a useful buffer against other, worse alien threats.
- The Elder Scrolls
- In the series backstory, there have been four empires founded by the races of Men - the short-lived 1st Era Nordic Empire and the three Cyrodiilic empires: the Alessian, Reman, and Septim. Each went through the cycle, with the first four games in the main series set during the (early) "Decay" phase of the Third Tamriellic (Septim) Empire. By the time of Skyrim, the "Long Night" is in effect: the Mede Dynasty (controlling the Vestigial Septim Empire) loses control of province after province, barbarian insurgents are everywhere, and agents of the rival Aldmeri Dominion (which is in the "Expansion" phase under the leadership of the extremist Thalmor) walk around Tamriel like it's their backyard.
- Other empires have had more localized versions. The Direnni Hegemony, for example, went through all the stages (rising from an Altmer (High Elf) clan from Summerset to dominating a third of Tamriel, centered around High Rock, and then shrinking back to only having the Isle of Balfiera — the Stabilization/Prosperity phases were evidently short), though they apparently managed to avoid most of the trappings of Vestigial Empire — the modern Dirennis are perfectly aware the Hegemony is gone, and are okay with that.
- The X-Universe has gone through The Cycle of Empire twice. In both cases, the Decline and Fall was due to somebody creating artificial general intelligence. The first time around, the Terrans nearly destroyed themselves, only surviving because the commander of their space navy lured the rogue terraformers through the Earth jumpgate, which was destroyed behind them. The survivors of said commander's fleet created a new civilization in the X-Universe, the Argon Federation. In the 2940s, threatened by Earth's superior military, the Argon created AGI warships and unleashed them on the Terrans, sparking an interstellar war that forced the Community of Planets the Argon were a part of to divert the military forces holding the terraformers (now called the Xenon) at bay. The Xenon went out of control, forcing the Ancients to shut down the jumpgate system. This caused Galactic/Societal Collapse, with all organized galactic government falling apart simultaneously and many star systems suffering an Inferred Holocaust. X Rebirth is set during the Interregnum about a thousand years later, and deals with the efforts to get the gates working again and build up to the Renaissance.
- Crisis of the Confederation is explicitly set during the Decay phase of the cycle for the Terran Confederation, with corruption and assorted injustices provoking a secession crisis along its periphery. Whether the crisis results in the Confederation eventually sliding into a Long Night or being reborn in a more vigorous and resilient form is up to the player and the game engine.
- The base game of Crusader Kings II starts during the Stabilization phase of the Holy Roman Empire's reign, going towards the start of the Decay. While ideally any kingdom under player control would start a new empire. The Charlemagne DLC goes back to the HRE's Expansion. Your own empire, should you choose to build one, can also be this: you can rapidly expand in the early game or at various points as you try to make one of the empires that can be formed in the game, and have peace and stability if you have a series of good kings and loyal nobles. However, external threats and scheming factions that prize their own ambitions over the kingdom as a whole can quickly bring your empire down, kick you off the throne (or outright murder your dynasty), or even split your empire up into parts once again.
- Stellaris has the player controlling a fledgling empire through its' expansion and pitting it against other empires as they also expand. As the empire grows larger it becomes harder and harder to hold together and the player finds themself fighting off rebellions as often as rival empires. They may also encounter Fallen Empires, highly-advanced empires that have stagnated. The Fallen Empires themselves have already been through this cycle, and are now in the decay portion (not completely gone but unable to expand), but when the Leviathans expansion came out for the game they now start to Awaken, starting the Expansion phase anew and becoming a very large threat. The 1.8 patch added a mechanic where after a rapid expansion they start to decay again, until their new subjects are able to overthrow them.
- The cycle of Light and Dark in Dark Souls can be likened to this. In the first game, the Expansion phase began when the four Lords declared war on the dragons and used the powers granted to them by the First Flame to vanquish them. Stabilization came with the Age of Fire, when the Lords ruled Lordran and Gwyn, Lord of Sunlight, created the city of Anor Londo. Decay started setting in when the Lords discovered that the First Flame was starting to fade, and their efforts to reignite it result in the creation/invasion of demonkind and Gwyn's throne being left empty. The game begins in earnest on the brink between phases 3 and 4, with an almost literal Long Night coming in the Age of Dark, though some claim it will also bring a golden age for humanity, leading them to a new Expansion phase.
- Final Fantasy XIV: the history of Eorzea is one of alternating Astral Eras and Umbral Eras, as civilizations rise to prominence, then fall into decay and vanish. Two such civilizations are the Allagan civilization, and the dual civilizations of Amdapoor and Mhach.
- The Allagan Empire of the Third Astral Era created technological marvels the likes of which have not been replicated, not even by the Magitek-empowered Garlean Empire. After constructing the solar-powered Crystal Tower, however, the civilization began to grow decadent and fall into decline. The civilization's brightest minds hoped to reverse the decline by cloning and resurrecting the first emperor, Xande. The pain of death, however, drove Xande to forge a pact with the Cloud of Darkness to cast all life into the Void. A failed experiment with the artificial moon of Dalamud would ultimately bury the entire civilization under a massive global earthquake.
- The civilzations of Amdapoor and Mhach were capitals of knowledge for both White and Black Magic, respectively. Both civilizations strove to improve their mastery over magic. In so doing, however, they began to seek means to subjugate each other, leading to the War of the Magi, a catastrophic conflict that nearly drained the entire planet of its aether and weakened the barrier between Hydaelyn and the Void. The War ended with the Sixth Umbral Calamity, a massive flood that wiped out both Amdapoor and Mhach. Survivors from both civilizations soon banded together and created what is now known as Red Magic: a school of magic that uses the caster's own aether instead of the planet. The disaster also caused the use of both Black and White Magic to be strictly regulated and forbidden to common folk ever since.
- The Galactic Empire from Crying Suns is teetering on the brink of Long Night. The OMNIs which managed all aspects of the Empires infrastructure shut down twenty years ago, preventing interstellar travel and communications. What remains of the Empire now governs a tiny sector centered on its capital, while the rest of its former territory is overrun by bandits and warlords.
- Orion's Arm has gone through the empire cycle at least once, after the fall of the First Federation Terragen space was divided into several "sephirotic empires". And it's indicated that the Sephirotics are fragmenting. That's despite they are ruled by Mega Giga AIs without human weaknesses. The authors never get tired of elaborating by how ludicrous a factor are their minds above puny human ones, but it seems that preventing the Cycle of Empires from completing is beyond their ability, too.
- This is more or less the basic model for the study of Chinese history. A dynasty is founded with the Mandate of Heaven, and renews/maintains the roads, dykes, levees and other infrastructure necessary to the health of the empire. Gradually, corruption and decay set in, the dynasty loses power to the eunuchs, literati, and local governors, and the infrastructure is no longer maintained. Eventually the old, rotten dynasty is deposed by a new one, who obviously was given the Mandate of Heaven to rule after the previous one had its divine favor revoked due to its wickedness and corruption.
- This cycle repeats itself throughout Mesopotamian history, with various empires and political bodies rising and falling, only to have their territory absorbed into the next empire. Starting with the Akkadian Empire of Sargon the Great in the twenty-fourth century BCE, we then have the Third Dynasty of Ur, the Old Assyrian Empire, the Isin-Larsa Period, the Babylonian Empire, the Hittite Empire, the Middle Assyrian Empire, the Neo-Assyrian Empire, and the Neo-Babylonian Empire, all of which controlled the same swathes of Iraqi and Syrian territory, and all of which eventually collapsed, only to be replaced by the next local dynasty. Then Cyrus the Great of Persia overran Neo-Babylonia, and established the Achaemenid dynasty, the first of the "Persian" Empires. Alexander the Great conquered the Achaemenids and one of his diadochi established the Seleucid dynasty. The Parthians rebelled against the Seleucids and gradually supplanted them. The Sasanians overthrew them to form the next Persian Empire only to be conquered by the Arabs. The Safavids reclaimed Persia, were overthrown by the Afshars, who were overthrown by the Qajar dynasty, who were invaded by the Ottomans and Russians during WWI and later overthrow by military coup forming the modern nation of Iran.
- Both the Hittites and Middle Assyrian Empire were caught up in the Bronze Age Collapse, the most widespread Decay/Long Night in history (although ironically the Assyrians were the one empire to somewhat avoid the usual cycle in it, cutting short phase 3 and 4 by abandoning their empire and focusing on their core territories, allowing a later reformation and comeback as the Neo-Assyrian Empire). The only civilisation at the time to come out unscathed was China, and that was only because they were doing entirely their own thing almost on the other side of the planet, everyone else either was pushed into complete collapse or at least reduced to a Vestigial Empire.
- The Trope Codifier for most Western audiences would be The Roman Empire. The Romans had their period of Expansionism lasting from their overthrow of the monarchy to its effective re-installation under Caesar Augustus. During this Republican period, Rome waged expansionist wars against various enemies, conquering Italy, North Africa, Greece, Gaul, Spain, Anatolia, Britain, much of the Middle East, and eventually Egypt. Under the emperors, the empire had a period of stabilization lasting from the end of the Triumvirate and the reign of Caesar Augustus until the Year of Five Emperors, a major civil war that saw the ascendance of the Severan Dynasty. It was then in a period of Decay, although it briefly had a period of stabilization under Constantine. The empire was split in two by Theodosius, and while the Eastern half would eventually have a period of resurgence and expansion under Justinian, the Western half continued its decay. By the middle of the 5th century, the Western Roman Empire was essentially in the Long Night phase, with the Emperor having increasingly little control over his own empire, which was constantly being divided by invading barbarian tribes or wracked by civil unrest. The Western Roman Empire officially ended with the death of Julius Nepos in 480 CE, but it had been effectively over for some time by that point.
- Genghis Khan's Mongol Empire, the largest contiguous Empire ever, averted the cycle. It fragmented within a generation of Genghis' death, while it was still in the expansion phase, and several of the shards continued to expand and stabilize as empires in their own right. Even after the Empire ended decisively in 1370 with the death of the last Khagan, the Golden Horde was still a major power (albeit one starting to get a little long in the tooth), the Timurid successor horde was in the first flush of expansion, and when China threw off the Mongol yoke, the Ming entered their own expansion. There was no Long Night for the Mongols or for most of their hordes, so much as a centuries-long period of churn between expanding empires.
- Russian history has gone through this sequence several times.
- First cycle: Rurik to Vladimir the Saint (expansion), Vladimir to Yaroslav the Wise (stability), Yaroslav's sons to Monomakh (decay), the Mongol yoke (Long Night).
- Second cycle: Ivan the Great (expansion), Ivan the Terrible (stability), Boris Godunov (decay), the Time of Troubles (Long Night). The First Romanovs' creation of the post-medieval Russia, which was more or less a recreation of Rurikid Muscovy as is, resulted in an Age of Rebellions (Buntashny Vek).
- Third cycle: Peter the Great (top-down revolution and expansion), Catherine the Great and Alexander I the Blessed (stability), Nicholas I to Nicholas II (decay), Provisional Government and the White Guards (Long Night). Note that in this cycle, the metrics for success can be misleading - Russia in 1913-17 was in the middle of an economic boom, with the highest levels of economic activity and prosperity the country had ever seen. But politically the country was in trouble because of the military's poor performance (because it was modeled and organised on 19th and not 20th-century/modern lines) and the reluctance of farmers to sell their grain on the open market as a result of the consumer-goods shortage (due to the 1915-16 mobilisation of all industry for Total War). The latter led to food shortages in Moscow and Saint Petersburg...
- Fourth cycle: Bolsheviks and pre-WWII Stalin (expansion), post-WWII Stalin and Khruschev (stability), Brezhnev to Gorbachev (decay), the Federal regime (Long Night). Hindsight may change these classifications - it's possible that perestroika and The New Russia are merely decay, and the real Long Night is yet to happen. Vladimir Putin is either a Diocletian, a strong ruler who has (for now) halted Russia's collapse in the middle of the decay phase, or a pompous gasbag of a dictator leading it to further ruin, depending on who you ask.
- A similar intuition forms the basis of a theory of how societies rise and fall put forward by economist Mancur Olson, in "Rise and Decline of Nations."
- The non-fiction book, The Accidental Superpower, separates the entire world into similar categories over the next 14 years, and examines some aforementioned historical cases (Ancient Egypt in the most depth). The map is based on population profiles (elderly to collect pensions, versus young to work, and middle aged to invest), available energy and food resources necessary to survive without freedom of navigation, as well as the separatism and the defensiveness of a nation's territory.