Hannibal, one of the greatest military leaders in history, accompanied his father Amílcar Barca at the age of nine on the Carthaginian expedition to conquer Spain. Before embarking, the boy swore eternal hatred for Rome, the bitter rival of his people. Twenty years later, in 218 a. C., he left Nueva Cartago (now Cartagena, Spain) to wage war in "The Eternal City" with an army of about 40,000, including cavalry and elephants.