Layamon's Brut (ca. 1190 – 1215), also known as The Chronicle of Britain, is a Middle English alliterative verse poem compiled and recast by the English priest Layamon. Layamon's Brut is 16,096 lines long and narrates a fictionalized version of the history of Britain up to the Early Middle Ages. It was the first work of history 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 French 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.
Like the earlier Latin works, it is now regarded as valueless as history. It gives the history of the Britons, largely ignoring the Anglo-Saxons. Its narrative ends with the Welsh king Cadwallon ap Cadfan, who died in 634.