Fri Dec 17, 2010 8:50pm EST

1 of 34. A Shi'ite Muslim man flagellates himself during an Ashura procession in Mumbai, India December 17, 2010.

Credit: Reuters/Danish Siddiqui

Ashura, the most important day in the Shi'ite calendar, commemorates the death of Prophet Mohammad's grandson Imam Hussein in battle 1,300 years ago.