Ахиезер

Haman (kneeling) convinces King Ahasuerus (Artaxerxes) that all disobedient people in his kingdom should be killed. Haman does not tell the king that he wants this just to be rid of his rival Mordecai.
By giving his ring to Haman, Ahasuerus acknowledges his consent.

Mediaeval illuminations on the story of Esther and Mordecai:
Queen Vashti Refuses to Appear before Ahasuerus | Haman Convinces Ahasuerus |