In the complex mythology of William Blake, Albion is the primeval man whose fall and division results in the Four Zoas: Urizen, Tharmas, Luvah/Orc and Urthona/Los. The name derives from the ancient and mythological name of Britain, Albion.
In the mythical story of the founding of Britain, Albion was a Giant son of Poseidon, the Greek god of the sea. He was a contemporary of Heracles, who killed him. Albion founded a country on the island and ruled there. Britain, then called Albion after its founder, was inhabited by his Giant descendants until about 1100 years before Julius Cæsar's invasion of Britain, when Brutus of Troy came and defeated the small number of Giants that remained (as a group of the Giants had killed all the others).
According to another myth, Noah's son Japhet had a son named Histion, who had four sons. Their names were Francus, Romanus, Brittos and Alemannus, and the French, Roman, British and German people are descended from them. Brittos divided Britain into three kingdoms and gave each to one of his sons. They were Loegria (a Latinization of the Welsh Lloegr, "England"), Scotland and Cambria.