The Thirty-first Dynasty of Egypt (notated Dynasty XXXI, alternatively 31st Dynasty or Dynasty 31), also known as the Second Egyptian Satrapy, was effectively a satrapy of the Achaemenid Empire between 343 BC to 332 BC. It was founded by Artaxerxes III, the King of Persia, after his reconquest of Egypt and subsequent crowning as Pharaoh of Egypt, and was disestablished upon the conquest of Egypt by Alexander the Great.
The period of the 31st Dynasty was the second occasion in which Persian pharaohs ruled Egypt, hence the term "Second Egyptian Satrapy". Before the 31st Dynasty was founded, Egypt had enjoyed a brief period of independence, during which three indigenous dynasties reigned (the 28th, 29th, and 30th dynasties). The period before this is referred to as the "First Egyptian Satrapy" or the 27th Dynasty (525–404 BC).
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