A fantasy setting with a twist by Harry Turtledove.
The first four books, known as The Videssos Cycle, started out as a Fan Fic of The Lord of the Rings by the young Turtledove in The '60s, in which the Witch-king of Angmar comes back from the dead after centuries and is the new antagonist for Fourth Age Gondor - only for a Roman legion to end up being transported through time and space to appear in the middle of this intrigue and conflict.
Turtledove then went to university and studied the history of the Byzantine Empire. He went back to his old story and created a new fantasy setting based on a fantastic version of Byzantine history (which is such an obscure subject to most Westerners that often only scholars could spot his references). The Big Bad was also reworked, though he retained two characteristics from the Witch-king: he never reveals his face, and he has a similar name ("Avshar"). The Videssos Cycle were some of Turtledove's first published novels, following the adventures of Marcus Aemilius Scaurus' Roman legion as they find themselves in this mysterious, decadent oriental empire - which, in a touch of dramatic irony, is but a fantastic version of the future of their own nation.
Since the publication of the original Cycle, Turtledove has written many short stories and novels which are all set before the Cycle books and deal with Videssian history before the magical appearance of the Romans.
The complete Videssos saga at present is as follows:
The Videssos Cycle (1987):
- The Misplaced Legion
- An Emperor for the Legion
- The Legion of Videssos
- Swords of the Legion
The Tale of Krispos (1991-94):
- Krispos Rising
- Krispos of Videssos
- Krispos the Emperor
The Time of Troubles (1995-98):
- The Stolen Throne
- Hammer and Anvil
- The Thousand Cities
- Videssos Besieged
Bridge of the Separator (standalone, 2005)
- The Decoy Duck
- A Difficult Undertaking
- The Seventh Chapter
Contains examples of:
- Age Without Youth: Avshar
- Alien Sky: The Romans only learn that they have been transported to another world, rather than just another part of Earth, when the sun sets and none of the constellations are recognisable.
- Anti-Magic: Marcus' and Viridovix' swords are of magical Druidic origin, and one of their two effects is to repel and negate any magic aimed at whoever wields them. Because they were magical even in our own unmagical world, they become so powerful in the magical-fantasy world of Videssos that even the greatest sorcerer in Videssian history is unable to overcome them.
- Ascended Fanfic
- Boisterous Bruiser: Viridovix. A Celtic chieftain before his entrance to Videssos, he's a charming man, a strong warrior, enjoys battle, and carries one of the two primary Macguffins of the series, and in many respects is a rival to the protagonist.
- Captain Smooth and Sergeant Rough: Marcus Aemilius Scaurus and Gaius Philippus respectively.
- Continuity Nod: In each series (Cycle, Krispos, Time of Troubles), there are references to chronologically previous series (that were published later). Cycle makes references to events in Krispos, To T, and Bridge. Krispos makes references to To T and Bridge. The references are just in passing, but a nice gem for those who have read the multiple series.
- Deadly Decadent Court: At least two, Videssos and Makuran. One of the major reasons why the Videssians are unable to effectively combat Avshar for so long in the original cycle is because they are too busy scheming against one another, eventually leading to more than one civil war.
- Evil Sorcerer: Avshar the wizard-prince of Yezd is an exceptionally powerful sorcerer and Magic Knight and the Dragon-in-Chief of the empire he allegedly serves. He's a vicious sadist who worships Skotos and is feared by allies and enemies alike, and always conceals his face behind a veil because he's Really 700 Years Old and suffers from Age Without Youth. Near the end of the series, he graduates to Sorcerous Overlord when he overthrows his "master", Khagan Wulghash, and takes over as overlord of the Yezda empire. It ultimately takes getting Dragged Off to Hell to stop him.
- Fantasy Counterpart Culture: Everywhere is based on a historical country or culture. Videssos is the Byzantine Empire, Makuran is Persia, Namdalen is Norman Sicily, and so forth.
- Fantastic Racism: As was the case in the real history the setting is derived from, the primary prejudice is based on religion rather than race. The Namdaleni call the Videssians 'Cocksures' as they are certain of Phos' victory over Skotos', while the Videssians call the Namdaleni 'Gamblers' because they only hope it will be certain, and the Khatrishers 'Balancers' as they believe Phos and Skotos are evenly balanced.
- Flat-Earth Atheist Marcus doesn't acknowledge that Photos and Skotos (the good and evil Gods of Videssianism) are real until one of them practically bites him on the ankle. To be sure, until then the main evidence for the gods' existence is that their priests can do magic—and as we find out in later books, priests of the completely different and incompatible Makuran religion can also do magic.
- Ho Yay: Between the gay Gorgidas and the skirt-chasing Viridovix. This is even called out by a character who briefly becomes Gorgidas's gay lover, causing an uncomfortable silence or two.
- Interfaith Smoothie: While the cultures map pretty closely to Earth counterparts, the religions are somewhat different. Videssos's religion has the bureaucratic structure of Byzantium's Orthodox Church, but a dualistic belief system much more like Persia's Zoroastrianism, with a conflict between a good god of light and an evil god of darkness. In Christian history, fights and schisms develop over questions of the Trinity and the Incarnation (e.g., is Jesus really human? Is the Son of God equal to God?); the Videssian equivalents are arguments about the relationship between the two Gods (is the evil god as powerful as the good one?). Makuran's religion is a thinly-veiled Islam (with a single God and four supreme Prophets), but at the time of the Cycle, it has been conquered by nomads (ruled by Avshar) who worship the evil Videssian god.
- Irony: As is often pointed out by readers (and Marcus himself wonders at one point what Rome would be like after centuries of being an imperial capital), the Romans are somewhat contemptuous of Videssos' decadent intrigue and overt religiosity, when of course they're seeing a Fantasy Counterpart Culture version of the future of their own people.
- Lost Roman Legion
- Loyal to the Position: Generally the case in Videssos. Especially apparent when Maniakes inherits most of the hated Genesios' palace staff in The Time of Troubles. Genesios, in turn, inherited them from the Avtokrator before him. In both cases the previous guy was overthrown by his successor.
- Sdrawkcab Alias: If you meet someone whose name is an anagram of "Avshar" ("Harvas", "Rhavas"), watch out.
- Sir Swears-a-Lot: Gaius Philippus. Probably his favourite oath is "Mars' left hairy nut!"
- Start of Darkness: Bridge of the Separator, for Avshar
- Tag Line: Somewhat unusually for a book, the one on the back cover of The Misplaced Legion was succinct and appropriate: NO ROADS TO ROME.
- Translation Convention: Latin and Videssian are both rendered as ordinary English, while Viridovix's Celtic accent is represented as a Scottish one, and archaic forms of Videssian are shown as archaic English (as Turtledove is a scholar, thankfully not Ye Olde Butcherede Englishe). Some formal and technical words in the "Videssian" language are actually Greek, the language of the Byzantine empire (e.g. "Avtokrator" for Emperor, "proskynesis" for a full prostration in the Emperor's presence), but the Greek-speakers in the Legion don't recognize the words.