Matter of Britain

The Matter of Britain (French: matière de Bretagne; Welsh: Mater Prydain; Cornish: Mater Brythain; Breton: Afer Breizh-Veur) is the body of medieval literature and legendary material associated with Great Britain and Brittany and the legendary kings and heroes associated with it, particularly King Arthur. The 12th-century writer Geoffrey of Monmouth's Historia Regum Britanniae (History of the Kings of Britain) is a central component of the Matter of Britain.

It was one of the three great Western story cycles recalled repeatedly in medieval literature, together with the Matter of France, which concerned the legends of Charlemagne and his companions, as well as the Matter of Rome, which included material derived from or inspired by classical mythology and classical history. Its pseudo-chronicle and chivalric romance works, written both in prose and verse, flourished from the 12th to the 16th century.

The three "matters" were first described in the 12th century by French poet Jean Bodel, whose epic Chanson des Saisnes [fr] ("Song of the Saxons") contains the lines:

Ne sont que III matières à nul homme atandant:
De France et de Bretaigne et de Rome la grant

There are only three subject matters for any discerning man:
That of France, that of Britain, and that of great Rome.

The name distinguishes and relates the Matter of Britain from the mythological themes taken from classical antiquity, the "Matter of Rome", and from the tales of the Paladins of Charlemagne and their wars with the Moors and Saracens, which constitute the "Matter of France".

King Arthur is the chief subject of the Matter of Britain. The others are stories related to the legendary kings of Britain, as well as lesser-known topics related to the history of Great Britain and Brittany, such as the stories of Brutus of Troy, Coel Hen, Leir of Britain (King Lear), and Gogmagog.

Geoffrey of Monmouth's Historia Regum Britanniae is a central component of the Matter of Britain. Geoffrey drew on a number of ancient British texts, including the 9th-century Historia Brittonum, the earliest known source of the story of Brutus of Troy. Traditionally attributed to Nennius, its actual compiler is unknown; it exists in several recensions. This tale went on to achieve greater currency because its inventor linked Brutus to the diaspora of heroes that followed the Trojan War. As such, this material could be used for patriotic myth-making just as Virgil linked the founding of Rome to the Trojan War in The Æneid. Geoffrey lists Coel Hen as a King of the Britons, whose daughter, Helena, marries Constantius Chlorus and gives birth to a son who becomes the Emperor Constantine the Great, thus tracing the Roman imperial line to British ancestors. It prominently included the King Arthur material, in which the post-Roman Britons led by Arthur briefly conquer much of Europe, including Rome itself, in the style of great world conquerors of antiquity.