Some time later King Xerxes promoted a man named Haman to the position of prime minister. Haman was the son of Hammedatha, a descendant of Agag.
References for Esther 3:1
The king ordered all the officials in his service to show their respect for Haman by kneeling and bowing to him. They all did so, except for Mordecai, who refused to do it.
The other officials in the royal service asked him why he was disobeying the king's command;
day after day they urged him to give in, but he would not listen to them. "I am a Jew," he explained, "and I cannot bow to Haman." So they told Haman about this, wondering if he would tolerate Mordecai's conduct.
Haman was furious when he realized that Mordecai was not going to kneel and bow to him,
and when he learned that Mordecai was a Jew, he decided to do more than punish Mordecai alone. He made plans to kill every Jew in the whole Persian Empire.