Layamon's Brut is one of the first major texts written in a Middle English dialect. From the scarce information that the author of the Brut supplies we know that he was a priest at Areley by the bank of the River Severn close to Redstone, which would indicate a south-west Midland dialect. He probably lived around 1200 and seemed to have been a learned clerk. The text survives in two British Library manuscripts. The dating to an exact year is not possible but it is generally agreed that it was composed in the first quarter of the thirteenth century, largely because of the mentioning of Queen Eleanor who died in 1204 and Layamon referring to her in the past tense.

The Brut is based on the Roman de Brut (1155) by the Norman Wace who relied heavily on Geoffrey of Monmouth's Historia Regum Britanniae (1138). The general contents of all three works is the same; a detailed account of the history of the Britons. This history begins with the fall of Troy and proceeds with the story of Brutus a descendant of Aeneas who journeys with other Trojans through the Mediterranean Sea until they finally reach the Isle of Avalon, inhabited by giants. These foes are killed and the isle renamed Britain after the founding father Brutus. What follows is an account of all British kings including such well known rulers as King Lear, Cymbeline and King Arthur. The Arthurian passage is the major part of the poem, with some 8.000 lines it makes up to half of the Brut. The major topic of Arthur's reign are his campaigns in which he succeeds to conquer the greater part of North-Western Europe. The most important campaign is against the Roman Emperor Lucius, who is defeated but the treachery of Mordred ends the British conquest and ultimately leads to the end of the Arthurian society with King Arthur being mortally wounded and brought to Avalon to return in times of great peril. The history ends with the last British King Cadwallader (AD 689).