King Ahasuerus taxed the entire kingdom, including the islands of the Mediterranean.
References for Esther 10:1
Now some may want to know about all the king's mighty, great deeds. They may also want a full report about how important Mordecai became after the king honored him. Are they not written in the official records of the kings of Media and Persia?
Certainly, Mordecai the Jew was second only to King Ahasuerus in importance. The Jews also admired him greatly, and his many brothers and sisters were proud of him. He always wanted to do good things for his Jewish people and to speak up for all his family whenever they needed help.