Xerxes I

American Heritage® Dictionary of the English Language, Fourth Edition

1. Xerxes I Known as "Xerxes the Great.” 519?-465 B.C. King of Persia (486-465) who organized a vast army that defeated the Greeks at Thermopylae and destroyed Athens (480). After the defeat of his navy at Salamis (480) and of his army at Plataea (479), he retreated to Persia, where he was later assassinated.

WordNet 3.0

1. n. king of Persia who led a vast army against Greece and won the battle of Thermopylae but was eventually defeated (519-465 BC)