Ascanius, who was also called Iulus, removed from Lavinium thirty years after its foundation, and built Alba Longa, or the "Long White City," on a ridge of the Alban Mount about fifteen miles southeast of Rome. It became the most powerful city in Latium, and the head of a confederacy of Latin cities. Twelve kings of the family of AEneas succeeded Ascanius. The last of these, named Procas, left two sons, Numitor and Amulius. Amulius, the younger, seized the kingdom; and Numitor, who was of a peaceful disposition, made no resistance to his brother. Amulius, fearing lest the children of Numitor might not submit so quietly to his usurpation, caused his only son to be murdered, and made his daughter, Rhea Silvia, one of the vestal virgins, who were compelled to live and die unmarried. But the maiden became, by the god Mars, the mother of twins. She was, in consequence, put to death, because she had broken her vow, and her babes were doomed to be drowned in the river. The Tiber had overflowed its banks far and wide; and the cradle in which the babes were placed was stranded at the foot of the Palatine, and overturned on the root of a wild fig-tree. A she-wolf, which had come to drink of the stream, carried them into her den hard by, and suckled them; and when they wanted other food, the woodpecker, a bird sacred to Mars, brought it to them. At length, this marvelous spectacle was seen by Faustulus, the king's shepherd, who took the children home to his wife, Acca Larentia. They were called Romulus and Remus, and grew up along with the sons of their foster-parents on the Palatine Hill. A quarrel arose between them and the herdsmen of Numitor, who stalled their cattle on the neighboring hill of the Aventine. Remus was taken by a stratagem, and carried off to Numitor. His age and noble bearing made Numitor think of his grandsons; and his suspicions were confirmed by the tale of the marvelous nurture of the twin brothers. Soon afterward Romulus hastened with his foster-father to Numitor; suspicion was changed into certainty, and the old man recognized them as his grandsons. They now resolved to avenge the wrongs which their family had suffered. With the help of their faithful comrades they slew Amulius, and placed Numitor on the throne.