The Twenty-seventh Dynasty of Egypt, also known as the First Egyptian Satrapy, was a satrapy of the Achaemenid Empire between 525 and 404 BC. It was founded by Cambyses II, the King of Persia, after the Battle of Pelusium and the Achaemenid conquest of Egypt, and his subsequent crowning as Pharaoh of Egypt. It was disestablished upon the rebellion and crowning of Amyrtaeus as Pharaoh. A second period of Achaemenid rule in Egypt occurred under the Thirty-first Dynasty of Egypt.