Layamon, or La3amon (using the archaic letter yogh), was a poet of the early 13th century, whose Brut (c. 1215) is a history of England in verse written in early Middle English. Although based on the earlier Roman de Brut written in Anglo-Norman by Wace (incorrectly known as Robert Wace), itself based on Geoffrey of Monmouth's Historia regum Britanniae, the poem is itself the first historiography written in English since the Anglo-Saxon Chronicle. Layamon's poem is also remarkable for its abundant Anglo-Saxon vocabulary; the scholar Roger Loomis counted only 150 words derived from Anglo-Norman in the 16, 000 long-lines. Many scholars believe the language of the poem to be intentionally archaised, rather than indicative of the Middle English commonly written and spoken during Layamon's lifetime. Layamon describes himself in his poem as a priest, living at Areley Kings in Worcestershire. His poem provided inspiration for numerous later writers, including Sir Thomas Malory and Jorge Luis Borges, and had an impact on medieval history writing in England.
The Brut's versification has proven extremely difficult to characterise. Written in a loose alliterative style, and sporadically deploying rhyme, as well as a caesural pause between the hemistichs of a line, it is perhaps closer to the rhythmical prose of Aelfric than verse per se. 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.