King Xerxes imposed taxes from one end of his empire to the other.
For the rest of it, King Xerxes' extensive accomplishments, along with a detailed account of the brilliance of Mordecai, whom the king had promoted, that's all written in The Chronicles of the Kings of Media and Persia.
Mordecai the Jew ranked second in command to King Xerxes. He was popular among the Jews and greatly respected by them. He worked hard for the good of his people; he cared for the peace and prosperity of his race.