Haman was the prime minister of Persia during the reign of King Xerxes. He is called an "Agagite," which suggests he was descended from the royal family of the Amalekites, as Agag was one of the titles of the Amalekite kings.
He was an arrogant man with an overinflated sense of his own importance. He became furious when Mordecai, a cousin of Esther, who was married to King Xerxes, refused to bow down to him.
When Haman saw that Mordecai would not kneel down or pay him honor, he was enraged. Yet having learned who Mordecai's people were, he scorned the idea of killing only Mordecai. Instead Haman looked for a way to destroy all Mordecai's people, the Jews, throughout the whole kingdom of Xerxes.
Haman had enough influence over the king to persude him to issue a royal edict to destroy, kill and annihilate all the Jews and to plunder their goods.
When Mordecai found out about this plot, he sent word to his cousin to tell her to use her relationship with the King to stop the massacre. The king arranged for a party to be throne to honor Haman, who was delirous with joy. But he said it was nothing compared compared to the pleasure he would get to see Mordecai dead.
His wife Zeresh and all his friends said to him, "Have a gallows built, seventy-five feet high, and ask the king in the morning to have Mordecai hanged on it. Then go with the king to the dinner and be happy." This suggestion delighted Haman, and he had the gallows built.
Haman, however, was to end up on the gallows himself, as Esther made the King understand that Haman's plot was against her own people.