Xerxes.
Depends which one, I'll assume you mean the most famous king of Persia, Xerxes I. Xerxes I of Persia ruled around the time of 480 BC. He succeeded his father Darius I who led an unsuccessful...
Xerxes was a son of the ruler Darius the First. He tried to conquer Greece again. In 480 BC, the Persian Army set out for Greece. They were also joined by the Persian Navy. I think they lost the war.