Haman was the evil and scheming prime minister of Ahasuerus (Xerxes 1), King of Persia (485-464 B.C.). When Mordecai refused to bow to Haman, Haman plotted to destroy Mordecai and his family, as well as all of the other Jews in the Persian Empire. But Esther intervened and saved her people. Haman was hanged on the very gallows that he had constructed for Mordecai (Esther 3:1-9).
Next person in the Bible: Hammoleketh (or Hammolecheth)