Ashura, meaning tenth in Arabic, refers to the tenth day of Muharram month under the Islamic lunar calendar. Shia Muslims mourn the martyrdom of Imam Hussain, the grandson of Prophet Mohammed, and his family members for ten days. The date of Ashura or Youm-e-ashura depends on the beginning of Muharram month. Imam Hussain and his followers were massacred in the battle of Karbala. In India, Ashura will be observed on September 10. Watch the video to find out why the battle of Karbala took place.