Xerxes I the Great (519–465 BC) became the Shahanshah (King of Kings) of the Achaemenid Persian Empire in 485 BC. Xerxes is the Greek form of the Persian Khashayar; he is also known in popular culture by his Hebrew name Ahasuerus. Xerxes sought to bring the various Greek city-states to heel, launching an invasion in 480 BC. Despite initially gaining the upper-hand, Xerxes' forces were eventually driven back by the Greeks, and Xerxes returned to Persia. He was murdered in 465 BC by one of his own generals.
Khsrish I the Conqueror was the King of Kings of Persia who conquered the Yauna and razed Athens, creating the greatest empire that the world had ever seen. Four centuries later, his descendant Khsrish IV attempted to capitalize on having this honored name, and sent the eunuch Mithredath to research important data regarding the original Khsrish.