The Imam flatly refused to give allegiance to the oppressive Umayyad caliph, Yazid.
His martyrdom took place on the tenth of the Muslim month of Muharram, known as Ashoura, in 680 AD.
He was martyred along with 72 of his loyal companions in the tragic massacre at Karbala.
The battle of Hussein is commemorated during an annual 10-day period
held every Muharram by the Shi'ah as well as many Sunnis or even other
religions culminating on its tenth day, Ashura.