Eustace the Monk (c.1170-1217), Benedictine monk, sea captain, and pirate, was the son of Baudoin Busket, a lord of the county of Boulogne. According to his biography, Eustace studied black magic in Toledo, returned home to become a monk at the abbey of St Samer near Calais, and then left the monastery to avenge the murder of his father.
It's as if we were twins.