The Welsh collection of stories called the Mabinogion is one of the major surviving bodies of Welsh myths. The stories in their modern forms are derived from two medieval Welsh manuscripts, the White Book of Rhydderch and the Red Book of Hergest, along with a collection of smaller texts, but those are simply the oldest written versions of stories that are based on older oral legends; some motifs and plots can be traced back to the early Iron Age (1st millennium BCE). They are the product of a highly developed narrative tradition, both written and oral.
The name is the plural of Mabinogi, somewhat archaic Welsh, but interestingly enough, the work should be called the "Mabinogi" since it consists of four branches of a single Mabinogi rather than multiple ones. A scribe made a mistake in the first branch, Pwyll Pendefig Dyfed, when he referred to it as the Mabinogion, which he later rectified in the other branches, but the name stuck. The best translation of "Mabinogi" appears to be "tales of childhood". Mab is the Welsh word for "son" (it's from the same root as the Gaelic mac), and the consonant-mutation "Vabinogi" occurs in "Llyma Vabinogi Iesu Grist", a medieval manuscript (Peniarth MS 14) describing the childhood of Jesus.
The work is divided into four branches, four native tales, and three romances. Also sometimes included is the Tale of Taliesin, though it belongs to a much later period.
The Four Branches create an Arc that follows the mythological heroes of Welsh pre-Christian mythology. The branches are connected by the struggles of the children of Llŷr and the life of Pryderi. They are, in order:
- Pwyll, Prince of Dyfed, detailing the journey of Pwyll into the kingdom of Annwn, the Celtic Otherworld. After returning to his own kingdom, he meets and wins his wife, the enchanted Rhiannon, from her unwanted suitor Gwawl. Pryderi is born, an event that initially brings more suffering than joy to his parents when he disappears mysteriously.
- Branwen, Daughter of Llŷr, is about the marriage of Branwen, sister of the king Bendigeidfran (Brân the Blessed), to the king of Ireland in a failed attempt to bring peace. The wrathful temper of her brother Efnysien starts a chain of events that ultimately destroys both kingdoms. Only seven Welsh soldiers survive the war, including Pryderi. The events of this branch lead directly into the next.
- Manawyddan, Son of Llŷr, in which Branwen's brother Manawyddan marries the now-widowed Rhiannon. Together with Pryderi and his wife Cigfa, they struggle against a series of disasters and curses perpetrated by Llwyd ap Cil Coed, friend of Gwawl from the first branch.
- Math, Son of Mathonwy, is nominally about the magician-king of Gwynedd, but most of the action centers around his nephew Gwydion fab Dôn for some reason.
- Gwydion first engineers a war — the war in which Pryderi is slain by Gwydion — to lure Math away from his castle so that Gilfaethwy, Gwydion's brother, can sneak into Math's stronghold and rape his foot-holder maiden, Goewin. In punishment, Math transforms the brothers into a different animal every year, one male and one female, until they bear three offspring together.
- Still up to mischief, Gwydion then suggests Goewin be replaced by his sister Arianrhod. Math puts her through a magical virginity test of stepping over a rod, causing her to promptly give birth. The child is largely shoved off-screen but Arianrhod also leaves a scrap of flesh that Gwydion keeps in a box and somehow becomes another boy.
- The rest of the narrative deals with Gwydion raising said boy and basically outwitting (or out-magicing) his sister's curses to deny Lleu Llaw Gyffes his name, arms, and a wife. Then finally Lleu's misadventures with his wife and Lleu becoming king. Phew!
Two of the native tales and the three romances are in the most part older versions of Arthurian Legend that differ slightly in the actual contents.
The native tales are:
- The Dream of Macsen Wledig describes the Roman Emperor Macsen (based on the real Emperor Magnus Maximus) who dreams of a beautiful woman in a magnificent land. He send off soldiers to find them, who lead him to a castle in (where else?) Wales where he finds and marries the woman, Elen. In the meantime the Empire is conquered by rebels, but fortunately Elen's brothers win it back for him.
- Lludd and Llefelys describes two royal brothers who team up to tackle various plagues inflicting the island of Britain. Notably contains an episode in which there are two dragons fighting (one white and one red), which later turns up in a slightly different form in Arthurian legends concerning Vortigern and Merlin.
- Culhwch and Olwen, perhaps the oldest Arthurian tale surviving. The young warrior Culhwch wants to marry the maiden Olwen, whose father is a formidable giant and sets Culhwch a series of seemingly impossible tasks (probably intended to kill Culhwch, or at least get him to stop pursuing Olwen). Culhwch enlists Arthur and his knights to help.
- The Dream of Rhonabwy, a late work in which the main character dreams of King Arthur's time, and particularly of Arthur lying in his cave, awaiting the time when he will return to free the island of Britain. It may have been written as deliberate fiction.
The romances are:
- Owain, or the Lady of the Fountain
- Peredur, son of Efrawg, part of King Arthur and the Holy Grail.
- Geraint and Enid
Apart from "The Tale of Taliesin", these three were the last parts of the Mabinogion to be composed, probably around the same time as most of the other medieval Arthurian stories, but draw on older roots.
In addition to the eleven tales listed above, a twelfth story, The Tale of Taliesin, is sometimes included as part of the Mabinogion (most notably in the earliest and most famous English translation, by Charlotte Guest). However, it was written down much later than the other texts (in the mid sixteenth century; versions of the other tales date to as much as five hundred years earlier).
The Mabinogion provides examples of:
- All There in the Manual: The Mabinogion is just one part of a much larger collection of epic prose and poetry spanning several centuries of Welsh culture. Events that seem out of nowhere, like the Giant Claw, are explained in other tales, many of which are sadly lost.
- Demoted to Extra: Half of Pwyll, Prince of Dyfed revolves around Pryderi's birth, abduction and reunion with his parents and Manawyddan, Son of Llŷr is about his return to Dyfed, but he only gets one mention in Branwen, Daughter of Llŷr and is promptly killed at the beginning of Math, Son of Mathonwy.
- Bag of Holding: Rhiannon gives a small bag to Pwyll in order to trick her unwanted suitor, Gwawl. It holds an entire feast's worth of food and, when he puts both feet into it, a grown man, with enough space to tie the bag closed over his head. It actually mentions that even if all the food and drink of seven cantrefs note were put into the bag, it would still not be full. One feast, no matter how grand, could not even come close to filling it.
- Color Motif: White, like the Cŵn Annwn ("hounds of Annwn"), had supernatural associations in early Celtic culture. The name of Arawn's enemy, Hafgan, means "summer white".
- Royals Who Actually Do Something: Pwyll defeats Arawn's enemy Hafgan and cements an alliance between Annwn and Dyfed.
- Knight Templar Big Brother: Efnysien mutilates a whole herd of horses because he didn't get to vet his sister's fiance.
- Meaningful Name: The names of Bran's brothers, the loving Nysien and the wrathful Efnysien, mean respectively "friendly one" and "hostile one". To highlight their differences, Nysien literally means "peace" and Efnysien also means not Nysien
- Polar Opposite Twins: Nysien is a gentle, peaceful man. Efnysien is a Sociopathic Hero who dies destroying the artifact that is letting the Irish win the war he started in the first place.
- Redemption Equals Death: Efnisien, the catalyst for the entire war, sacrifices himself to clinch victory for the Britons.
- Rule of Three: Triads is a narrative device in Welsh lore that links stories together. For example, Branwen is one of the Three Main Parents, the other two being Rhiannon and Aranrhod.
- Sociopathic Hero: Efnisien is psychotic, warped, and cruel, but he ultimately sacrifices himself for the few remaining Britons.
- Would Hurt a Child: Efnisien has no qualms throwing his infant nephew into the fire out of jealousy and anger.
- Ambiguous Syntax: Lleu Llaw Gyffes is occasionally referred to as "[Gwydion's] boy", although the word boy can also mean "son". This is either a subtle hint that Lleu was born from a Brother–Sister Incest between Gwydion and Arianrhod, or simply a reference to Gwydion's role as Lleu's Parental Substitute.
- Artificial Human: Blodeuedd is born when Gwydion and Math club together to find a wife for Lleu, crafting her from the flowers of broom, meadowsweet and oak.
- Born from Plants: The perfect woman Blodeuwedd is created from the flowers and growing things of the earth: her hair is effectively made of flowers. Later, for her sins and heartlessness, she is turned into the first owl and fated to haunt the night — the flowers that became human hair now mutate into feathers.
- Cool and Unusual Punishment: Gwydion and Gilfaethwy are transformed into a different pair of breeding animals each year for three years as punishment.
- Fate Worse than Death: Blodeuwedd is forced to live for all eternity as an owl, shunned by the light and hated by all other birds, which Gwydion considers to be a worse punishment than simply killing her.
- Gender Bender: Biologically male, Gwydion and Gilfaethwy alternate being female throughout their punishment for the rape of Goewin.
- Karmic Transformation: As punishment for the rape of Goewin, King Math transforms the brothers Gilfaethwy and Gwydion into different animals each year, one a male and one a female, until they have borne three offspring together. Later on, Blodeuwedd is transformed into an owl as punishment for plotting with her lover, Gronw Pebr to kill her husband.
- Magic Knight: Gwydion defeats Pryderi in one on one combat, and he once animated an entire forest of trees to serve as an army against Arawn.
- Mister Seahorse: Gwydion and Gilfaethwy, two men, are successively turned into a stag and a hind, a boar and a sow, and a pair of wolves. They are in these forms long enough to bear a son from each transformation. After the brothers are turned back into redeemed humans, their animal offspring are then turned into humans and baptized.
- Nigh-Invulnerability: Lleu can be killed, but only under extremely specific circumstances. He has to be struck while he has one foot on the back of a billy-goat and one on the edge of a roofed bath that sits on a riverbank. In his own words: "I cannot be killed indoors, nor out of doors; I cannot be killed on horseback, nor on foot." The spear it would take to kill him needs to be forged over a year of Sundays. Even when his rival actually got to attack him in that position, he doesn't die but was simply injured.
- Parental Substitute: Gwydion raises Lleu into adulthood after his mother makes it clear that she's ashamed of his birth.
- Villain Protagonist: In the first act, the protagonist Gwydion engineers a war with the south (which leads to the deaths of hundreds of warriors, including King Pryderi of Dyfed) only to get Math out of the palace just so Gwydion's brother can rape Math's footholder, Goewin.
- Was Once a Man: Prior to being turned into an owl, Blodeuwedd was an Artificial Human.
- Achilles in His Tent: Cai leaves the band in a sulk after Arthur sings a satirical verse at him.
- Badass Crew: Culhwch and his companions break Mabon ap Modron out of the tower he's been imprisoned in since he was three days old and hunt an enchanted boar with poisonous bristles.
- Early-Installment Weirdness: Arthur's court is not at Camelot but at Celliwig in Cornwall. He also has several sons, and the only knights recognizable from later stories (if barely) are Kay, Bedivere, and Gawain. Many of the knights have magical powers and use these regularly.
- Engagement Challenge: Culhwch is cursed by his Wicked Stepmother that he can marry no one but the daughter of Ysbaddaden the Giant, who claims that he cannot prepare for the ceremony until Culhwch hunts the giant boar Twrch Trwyth and retrieves a comb, scissors and razor from his hair. But he can only be tracked by a certain hound, and the leash can only be made by a certain hero but held by another until the job involves over forty different tasks and no less than King Arthur and his warband.
- Eye Scream: Early on, Ysbaddaden throws a poisoned javelin at Culhwch, who catches it and throws it back through Ysbaddaden's eye and head, leaving it protruding out the nape of his neck. Ysbaddaden yells about this for a bit.
- Fertile Feet: White trefoils spring up in Olwen's footsteps.
- Full-Boar Action: Twrch Trwyth can't be hunted except with certain hounds, has poisonous bristles and requires the likes of Gwyn ap Nudd (legendary leader of The Wild Hunt), to help bring him down.
- Handicapped Badass: Bedwyr, the one-armed knight, can draw blood on the battlefield before anyone else.
- Important Haircut: King Arthur cuts Culhwch's hair in the presence of his court at the beginning of the story. In Medieval Britain, this was an important gesture of fidelity between family and clan members. Arthur is symbolically accepting his younger cousin into his retinue, which then allows Culhwch to ask for his assistance in gaining Olwen.
- Long List: The Story contains a list of King Arthur's companions which numbers at around 260 names, and takes up about four pages in some editions.
- Major Injury Underreaction: Ysbaddaden speaks pretty calmly (if resentfully) to Olwen after a minor character cuts the flesh off the giant's face down to the bone. There's also the three scenes where he throws poisoned javelins at our heroes, who catch them and throw them back: straight through his kneecap, chest, and head. All he does in response is complain about how much they hurt.
- Outliving One's Offspring: Goreu's parents lost their twenty-three elder children to Ysbaddaden, and Arthur's son Gwydre is killed during the hunt of Twrch Trwyth.
- Wolverine Publicity: Gawain is assigned by King Arthur as Culhwch's companion, but takes no part in the adventure which is mentioned. As such, there is a theory that he was, indeed, written in later due to his fame.