Numitor was the king of Alba Longa, and the maternal grandfather of Rome's founder and first king, Romulus, and his twin brother Remus.
In 794 BC Procas died and was meant to be succeeded by Numitor. Instead he was overthrown and removed from the kingdom by his brother, Amulius, who had no respect for his father's will or his brother's seniority. Amulius also murdered his sons, in an effort to remove power from his brother for himself.
Rhea Silvia was made a Vestal Virgin by Amulius rendering her unable to have children on pain of death; however, she was forcibly impregnated by the god Mars. Romulus and Remus overthrew Amulius and reinstated Numitor as king in 752 B.C