"Having decided to crush Husayn and the Kufan revolt by force, Yazid sent an army of thousands to the area. They laid siege to Husayn's caravan, whose male members (except for Husayn's ailing son, Ali) put up a valiant resistance. Among Shias, the gallantry of Husayn and his brother and standard-bearer Abbas are legendary. Dug in with their backs to a range of hills, Husayn and his men held off the Syrian army for six grueling days. Then the Umayyad general Shimr, a figure forever damned in Shia lore, managed to cut off Husayn's troops from their source of water, thereby forcing a fight in the open. Nerved by a courage born of desperation and a stead-fast belief in the rightness of their cause, Husayn and his parched, outnumbered men bravely charged the much larger Umayyad army, only to be cut down and massacred. The fallen were beheaded; their bodies were left to rot in the scorching heat of the desert, and their heads were mounted on staffs to be paraded in Kufa before being sent to the caliph in Damascus. Husayn's body, along with those of his companions, was buried on the battlefield by local villagers. Shia legend has it that an artist drew Husayn's noble countenance as it awaited display at Yazid's court. That image of Husayn, in a majestic pose with arched eyebrows and piercing eyes, the Shia believe, is the same that adorns shop windows in Karbala and is carried in Shia processions. Egyptians claim that Husayn's head was buried in Cairo, where today the Sayyidina Husayn (Our Lord Husayn) Mosque stands at the mouth of the Khan Khalili bazaar.
Husayn's sister, Zaynab, accompanied her brother's head to Damascus. There she valiantly and successfully defended the life of the lone surviving male member of the family, Husayn's son, Ali, who would succeed his father as the fourth Shia imam, thereby ensuring the continuity of Shiism. Zaynab bore witness to Karbala and lived to tell the tale. That Husayn's heroism became legendary and gave form to Shiism is very much her doing: Shiism owes its existence to a woman. It celebrates the strong characters and bravery of female figures in a way that has no parallel in Sunnism. Women like Zayab and her mother, Fatima, played major parts in Shia history and fill a role in Shia piety not unlike the one that the Virgin Mary plays in the popular devotionalism of Catholic and Orthodox Christianity. Zaynab lived most of her life in Cairo, and a mosque popular with women sits where her home once stood. She is buried in Damascus; her shrine, the mosque of Sayyida Zaynab (Lady Zaynab), is a popular place for Shia pilgrims to visit."
-Vali Nasr, The Shia Revival