Brut, legendary first king of Britain. According to tradition, Brut (the French form of Brutus) was the grandson or great-grandson of the Trojan hero Aeneas. A fugitive, he wandered north, founded the city of London, and sired a long line of British kings, including the semilegendary Arthur. The legend appears first in Latin as recounted in Historia Regum Britanniae (1136?; History of the Kings of Britain) by the 12th-century Welsh writer Geoffrey of Monmouth; it was translated (1175) into Old French in Roman de Brut by the Anglo-Norman poet Wace; and it was first related (circa 1200) in English by the poet Layamon.