Esther 3:1-2, 5-6

Some time later, King Xerxes promoted Haman son of Hammedatha the Agagite, making him the highest-ranking official in the government. All the king’s servants at the King’s Gate used to honor him by bowing down and kneeling before Haman—that’s what the king had commanded.

When Haman saw for himself that Mordecai didn’t bow down and kneel before him, he was outraged. Meanwhile, having learned that Mordecai was a Jew, Haman hated to waste his fury on just one Jew; he looked for a way to eliminate not just Mordecai but all Jews throughout the whole kingdom of Xerxes.