Romulus and Remus were the legendary founders of Rome. In Roman mythology they were twin brothers, children of Rhea Silvia and the god Mars.
Rhea Silvia was the daughter of Numitor Silvius, king of Alba Longa, a legendary town founded by Ascanius, son of Aeneas, prince of Troy. When Numitor's brother Amulius became king by force, he made Rhea Silvia a Vestal Virgin, so she would not have children who could be kings instead of him. But the god Mars seduced her and she had the twins Romulus and Remus. Rhea Silvia was punished, and her sons were thrown into the Tiber, but were saved by the river god Tiberinus, who also saved Rhea Silvia and married her. Romulus and Remus were found by a she-wolf who suckled them. A woodpecker fed them. The brothers were later found by a shepherd, Faustulus, who raised them.
Once they were grown, Romulus and Remus founded the city of Rome. However, the twins had an argument about where to start Rome. Romulus favored the Palatine Hill, but Remus favored the Aventine Hill. They decided to settle the disagreement by asking the gods. Each brother stood on his respective hill. Remus saw six birds fly overhead, and Romulus saw twelve. However, Remus countered that he had seen the birds first. Nonetheless, Romulus started to build a wall around his city. Then, Remus jumped over the wall as an insult to his brother. Angered, Romulus killed Remus. He regretted it, and took Remus to Amulius's palace, and buried him there.
SOURCE - Simple English Wikipedia