Husain ibn Ali was the grandson of the Prophet Muhammad and the son of Ali ibn Abi Talib and Fatimah. Born in 626 CE in Medina, he is revered in both Sunni and Shia Islam for his piety and leadership. Husain is best known for his role in the Battle of Karbala in 680 CE, where he stood against the Umayyad caliph Yazid I, refusing to pledge allegiance to a ruler he considered unjust. The events at Karbala are significant in Islamic history, particularly for the Shia community, symbolizing the struggle against tyranny and injustice. Husain's martyrdom is commemorated annually during the month of Muharram, especially on the day of Ashura, when millions of Muslims participate in mourning rituals to honor his sacrifice and uphold his message of righteousness.