Among Shia Muslims, Arbaeen commemorates the end of the mourning period for Imam Hussein, an important figure who died in 680 at the battle of Karbala, located in present-day Iraq.
As one of the most important dates for this community, Shias from all over the world come to pay their respects at the mausoleum erected on the site of his death. In 2023, 20 million Shia pilgrims, from Iraq, Iran, but also from Afghanistan and Pakistan, made the journey to this holy city two hours' drive south of Baghdad. Largely repressed under Saddam Hussein's reig, this pilgrimage has grown to become the largest gathering of human beings in the world.