Muslim pilgrims walk to the holy city of Karbala ahead of the Shiite ritual of Arbaeen, in Najaf, Iraq, on Nov. 30, 2015. Arbaeen marks the end of a 40-day mourning period for the killing of the Prophet Muhammad's grandson Hussein 13 centuries ago. Photo courtesy of Reuters/Alaa Al-Marjani
*Editors: This photo may only be republished with RNS-ARBAEEN-PILGRIMAGE, originally transmitted on Dec. 3, 2015.
(RNS) Drawing an estimated 17 million pilgrims, the Shiite ritual known as Arbaeen dwarfs even the hajj. Arbaeen marks the end of the 40-day mourning period after the anniversary of the seventh-century slaying of the Prophet Muhammad's grandson, which engendered the Sunni-Shiite schism.