Why Karbala Is So Famous ????

The Battle of Karbala took place on Muharram 10, in the year 61 AH of the Islamic calendar[2] (October 10, 680)[8][9] in Karbala, in present day Iraq. The battle was between a small group of supporters and relatives of Muhammad's grandson Hussein ibn Ali, and a much larger military detachment from the forces of Yazid I, the Umayyad caliph, whom Hussein had refused to recognise. Hussein and all his supporters were killed, including Hussein's six-month-old infant son, Ali al-Asghar ibn Husayn, and the women and children taken as prisoners. The dead are regarded as martyrs by Muslims, and the battle has a central place in Shia history and tradition, and has frequently been recounted in Shia Islamic literature.

The Battle of Karbala is commemorated during an annual 10-day period held every Muharram by the Shia and Alevis, as well as many Sunnis, culminating on its tenth day, Ashura.
Shias believe Hussain's sacrifice was ordered by God and was necessary to awaken the ummah and stop Yazid hijacking Islam.