Mempricius (Welsh: Meinbyr) was a legendary king of the Britons asaccounted by Geoffrey of Monmouth. He was the son of King Maddan andbrother of Malin.
Upon his father's death, war broke out between Mempricius and hisbrother, Malin, over who would dominate Britain. Mempricius called aconference with his brother and other delegates to end the war betweenthe two brothers. Once there, Mempricius killed Malin and took the throneof the Britons for himself. He ruled as a tyrant for twenty years,killing most of the distinguished men on the island. More so, he defeatedand killed all other claimants to the throne. He abandoned his wife andhis son, Ebraucus, to live a life of sodomy. While on a huntingexpedition, he was separated from his companions and attacked by a packof wolves. He died and was succeeded by his son Ebraucus.
These events corresponded to the reign of Saul in Judea and Eurysthenesin Sparta.