Layamon's Brut (ca. 1190 - 1215), also known as The Chronicle of Britain, is a Middle English poem compiled and recast by the English priest Layamon. The Brut is 16,095 lines long and narrates the history of Britain: it is the first historiography written in English since the Anglo-Saxon Chronicle. Named for Britain's mythical founder, Brutus of Troy, the poem is largely based on the Anglo-Norman Roman de Brut by Wace, which is in turn a version of Geoffrey of Monmouth's Latin Historia Regum Britanniae. Layamon's poem, however, is longer than both and includes an enlarged section on the life and exploits of King Arthur. It is written in the alliterative verse style commonly used in Middle English poetry by rhyming chroniclers, the two halves of the alliterative lines being often linked by rhyme as well as by alliteration.
The versification of the Brut has proven extremely difficult to characterise. Written in a loose alliterative style, sporadically deploying rhyme as well as a caesural pause between the hemistichs of a line, it is perhaps closer to the rhythmical prose of Ælfric of Eynsham than to verse, especially in comparison with later alliterative writings such as Sir Gawain and the Green Knight and Piers Plowman. Layamon's alliterating verse is difficult to analyse, seemingly avoiding the more formalised styles of the later poets.