Who ruled Persia before Darius?

Before Darius I, Persia was ruled by Cyrus the Great, who founded the Achaemenid Empire and expanded it significantly during his reign from 559 to 530 BCE. Following Cyrus, his son Cambyses II took the throne, ruling from 530 to 522 BCE, and he is known for his conquest of Egypt. After Cambyses, there was a brief period of instability and a power struggle before Darius I ascended to the throne.