King Xerxes was king of Persia from 486-465 BC. His wife was Queen Amestris. King Xerxes was murdered by Artabanus, who then gave the position of power to his seven sons. According to Aristotle, Artabanus was then killed by Artaxerxes, son of Xerxes and Amestris.
This draws interesting parallels to FMA, where the country of Xerxes was destroyed by Father. Father then created the seven homunculi, and gave the highest position of power in the country to one of his sons, and the other homunculi watched over the Amestrian cities.
It is fitting, that Father, like Artabanus, was killed by Edward Elric, with a mother from Amestris, and a father from Xerxes. Like Artaxerxes, Ed avenged the Xerxesian people by dealing the final blow on Father.