Arbaeen is a significant religious event observed exclusively by Shia Muslims. The word "Arbaeen" translates to "forty" in Arabic, signifying the end of a 40-day mourning period for the Prophet Muhammads grandson, Hussein ibn Ali, the third imam of the Shia tradition. Arbaeen occurs forty days after the Day of Ashura, which commemorates the martyrdom of Imam Hussein. Imam Hussein and 71 of his companions were martyred in the Battle of Karbala in 61 AH (680 CE).
During Arbaeen, hundreds of thousands of Shia Muslims gather in the holy city of Karbala in Iraq, making it the world's largest peaceful gathering. The event is marked with mass walks to Karbala from cities across Iraq, with the number of participants said to number in the millions. This pilgrimage to the shrine of Imam Hussein is known as the Arba'in pilgrimage.
On the day of Arbaeen, the participants recite a prayer called Ziyarat Arbaeen, which affirms their allegiance to Hussein's ideals. The prayer designates Hussein as the "inheritor" of the message brought down by the prophets Adam, Noah, Abraham, and others. Arbaeen is also known for its humanitarian aspect, with up to 25 million pilgrims being fed for free and the largest group of volunteers serving a single event in the world.
