He is described as a legendary descendant of the Trojan hero Aeneas, known in medieval British legend as the eponymous founder and first king of Britain.

Some have suggested that attributing the origin of 'Britain' to the Latin 'Brutus' may be ultimately derived from Isidore of Seville's popular 7th-century work Etymologiae (c. 560–636), in which it was speculated that the name of Britain comes from bruti, on the basis that the Britons were, in the eyes of that author, brutes, or savages.

[1] A more detailed story, set before the foundation of Rome, follows, in which Brutus is the grandson or great grandson of Aeneas – a legend that was perhaps inspired by Isidore's spurious etymology and blends it with the Christian, pseudo-historical, "Frankish Table of Nations" tradition that emerged in the early medieval European scholarly world (actually of 6th-century AD Byzantine origin, and not Frankish, according to historian Walter Goffart)[2] and attempted to trace the peoples of the known world (as well as legendary figures, such as the Trojan house of Aeneas) back to biblical ancestors.

[3][4][5][6] Supposedly following Roman sources such as Livy and Virgil, the Historia tells how Aeneas settled in Italy after the Trojan War, and how his son Ascanius founded Alba Longa, one of the precursors of Rome.

After wandering among the islands of the Tyrrhenian Sea and through Gaul, where he founded the city of Tours, Brutus eventually came to Britain, named it after himself, and filled it with his descendants.

He becomes their leader, and after a series of battles they defeat the Greek king Pandrasus by attacking his camp at night after capturing the guards.

After performing the appropriate ritual, Brutus falls asleep in front of the goddess's statue and is given a vision of the land where he is destined to settle, an island in the western ocean inhabited only by a few giants.

After some adventures in north Africa and a close encounter with the Sirens, Brutus discovers another group of exiled Trojans living on the shores of the Tyrrhenian Sea, led by the prodigious warrior Corineus.

The Trojans win most of their battles but are conscious that the Gauls have the advantage of numbers, so go back to their ships and sail for Britain, then called Albion.

After his death he is buried in Trinovantum, and the island is divided between his three sons: Locrinus (England), Albanactus (Scotland) and Kamber (Wales).