Purim is a joyful Jewish holiday celebrated on Adar 14 every year. This year on March 7. Officially, it begins on Monday evening, March 6, and lasts through Tuesday, March 7, outside Jerusalem. Only in Jerusalem is Purim a day later than in the rest of the world. The day commemorates the Eternal-organized rescue of the Jewish people in the ancient Persian Empire.
The first minister at the time, Haman, had devised a plan to destroy all Jews, young and old, babies, men and women, in one day. Haman let fate determine when he would carry out his diabolical plan. The festival is named after this, because the lot, plural: lots, is in Hebrew: Purim. It’s a celebration because his plan failed.
The Jews were allowed to defend themselves at the hands of the wife of King Ahasuerus, the Jewish queen Hadassah, who was called Esther there. She was supported in this by her uncle Mordechai. All this is recorded in the Megillat Esther, the Epistle of Esther. Este did not reveal her Jewish identity, hence the masks on Purim. Likewise, the name of the Eternal or any reference to Him does not appear in this letter, so anonymous is also a theme in this feast.