Why Rome had only 7 Kings

The transcript describes the tyrannical rule of Tarquin, who murdered his father-in-law and killed senators to secure his power. His son's threat to Lucretia led to a revolt led by Brutus, who defeated Tarquin and vowed that Rome would never again be ruled by a king.

How did the king rule over his subjects?

What did Brutus swear after defeating Tarquin?