Amulius exiled king Numitor out of his kindom, Alba Longa.
Rhea Silvia, Numitor's daughter, got the role of being a Vestal Virgin because Amulis heard that Rhea Silvia's sons would overthow him. Even though she was a Vestal Virgin, she had a child with Mars.
Because Rhea Silvia had children, she was sentenced to death. King Amulius sent two men to her house to steal the twins and drown them in the Tiber river so they would not overthrow him. The men felt bad about killing royalty so they sent them down the river.
A she-wolf found the twins and brought them in as her own. I passing shepherd, Faustulus, noticed the twins. He snuck into their cave and took the twins home to his wife.
One day a man lost his cattle and Romulus and Remus brought the cattle back to the man. It turns out that the man was their grandfather Numitor and they made a plan to get him back to being king.
Romulus and Remus killed Amicus, and Numitor became king again. Romulus and Remus wanted to start a city near where the she-wolf found them. They got in an argument about what their city would be called, so Remus kicked one of Romulus' walls and Romulus ended up killing his brother Remus. That is the origin of Rome.