Which Achaemenid king conquered Egypt in 525 BCE?

Cambyses II conquered Egypt in 525 BCE. He was the second king of the Achaemenid Empire and succeeded his father, Cyrus the Great, around 530 BCE.

Cambyses led the Persian invasion into Egypt and defeated Pharaoh Psamtik III at the Battle of Pelusium. Memphis fell soon afterward, bringing Egypt into the Achaemenid imperial system as a Persian province, or satrapy.

Cambyses is sometimes confused with Darius I, who later reorganized Persian rule in Egypt and sponsored major building projects there. Cambyses also campaigned southward toward Nubia and westward against Carthaginian interests, although accounts of his later expeditions vary in reliability.