The Battle of Karbala

The Battle of Karbala took place on Muharram 10, in the year 61 AH of the Islamic calendar (October 10, 680 AD) in Karbala, in present-day Iraq. The battle took place between a small group of supporters and relatives of Muhammad's grandson, Husayn ibn Ali, and a larger military detachment from the forces of Yazid I, the Umayyad caliph.
When Muawiyah I died in 680, Husayn did not give allegiance to his son, Yazid I, who had been appointed as Umayyad caliphby Muawiyah; Husayn considered Yazid's succession a breach of the Hasan–Muawiya treaty. The people of Kufa sent letters to Husayn, asking his help and pledging allegiance to him, but they later did not support him. As Husayn traveled towards Kufa, at a nearby place known as Karbala, his caravan was intercepted by Yazid I's army led by Al-Hurr ibn Yazid al Tamimi. He was killed and beheaded in the Battle of Karbala by Shimr Ibn Thil-Jawshan, along with most of his family and companions, including Husayn's six month old son, Ali al-Asghar, with the women and children taken as prisoners. The battle was followed by later uprisings namely, Ibn al-Zubayr, Tawwabin, and Mukhtar uprising which occurred years later.
The dead are widely regarded as martyrs by Sufi, Sunni and Shia Muslims. The battle has a central place in Shia history, tradition and theology and it has frequently been recounted in Shia Islamic literature. Mainstream Sunni Muslims, on the other hand, do not regard the incident as one that influences the traditional Islamic theology and traditions, but merely as a historical tragedy.
The Battle of Karbala is commemorated during an annual 10-day period held every Muharram by Shia and Alevi, culminating on its tenth day, known as the Day of Ashura. Shia Muslims commemorate these events by mourning, holding public processions, organizing majlis, striking the chest and in some cases self-flagellation.
The Battle of Karbala played a central role in shaping the identity of Shia and turned the already distinguished sect into a sect with "its own rituals and collective memory." Husayn's suffering and death became a symbol of sacrifice "in the struggle for right against wrong, and for justice and truth against wrongdoing and falsehood."