Answer
Artabanus, the captain of Xerxes I's bodyguard, assassinated the Persian king in 465 BC. Artabanus's motives are unclear, but he may have been motivated by a desire for power or revenge. He conspired with other high-ranking officials to kill Xerxes and then seized the throne for himself. Artabanus's reign was short-lived, as he was assassinated by Xerxes' son, Artaxerxes I, the following year.