On November 9, 2017, millions of black-clad Shia pilgrims converged on the holy city of Kerbala for the Arbaeen religious commemoration, the largest annual gathering of people anywhere on earth. Walking in long columns stretching back unbroken for as much as 50 miles, sleeping and eating in tents erected by supporters beside the road, the event has become an overwhelmingly powerful display of Shia belief and solidarity.
Here are photos of the event:
