In 1610, after his father's discharge because of a navy reorganization, the Tromps were on their way to Guinea on their merchantman when they were attacked by a squadron of seven ships under command of the English pirate Peter Easton. During the fight, Tromp's father was slain by a cannonball. According to legend, the 12-year-old boy rallied the crew of the ship with the cry "Won't you avenge my father's death?" The pirates seized him and sold him on the slave market of Salé. Two years later, Easton was moved by pity and ordered his redemption.