Imam Husayn's martyrdom took place on the 10th day of Muharram, 61 A.H. (October, A.D. 680) The first ten days of Muharram are observed by Shi'ih Muslims as a period of mourning for the Imams, ending on the tenth day with the Ashura, the commemoration of the martyrdom of the Imam Husayn. A grandson of Prophet Muhammad, Husayn was born to 'Ali and Fatimah (Muhammad’s daughter) in January 626. (Adapted from ‘The Prince of Martyrs’, by Abu'l-Qasim Faizi; ‘A Basic Baha’i Dictionary’, by Wendi Momen; and ‘Muhammad and the Course of Islam’, by Balyuzi)