Arbaeen is a significant religious observance in the Shia Muslim community, marking the end of the mourning period for the martyrdom of Imam Hussein, the grandson of the Prophet Muhammad. It occurs 40 days after Ashura, the day of Imam Hussein's death at the Battle of Karbala in 680 CE. During Arbaeen, millions of pilgrims travel to the holy city of Karbala in Iraq to pay their respects. The event is characterized by processions, prayers, and acts of charity, emphasizing themes of sacrifice, justice, and remembrance of the struggles faced by Imam Hussein and his followers.