There was an 180 day long festival that King Ahasuerus held before invading Greece, during that time he got very drunk. He summoned his wife Vashti, so he could show off how beautiful she was. She refused to come and in turn she lost her position as queen.  

When Ahasuerus returned from Greece he chose another queen. A young Jewish girl named Esther was raised by her cousin, Mordecai. But she kept the fact that she was a Jew a secret.

Haman was an Agagite and he hated the Jews. He hated them so much that he went to the king and asked him to make a decree that all the Persians should kill the Jews. Expect he didn’t tell him that he wanted the Jews killed. Mordecai told Esther of Haman’s plans, he told her to go to the king and ask him to take back that decree. She agreed and went to the king, after telling him what Haman was planning to do. Ahasuerus was furious, he hung Haman and made a new decree that the Jews were allowed to fight back the day they were supposed to be killed.  

After all of these events there was a feast that was held named Purim.