The captives were taken to Kufa where Zaynab, Imam Husayn's sister is defiant in the face of ibn Ziyad, one of battlefield commanders. They are forced to travel to Damascus where Yazid gloats over the head of Imam Husayn and insults Ali and Zaynab, the only family who survived the massacre at Karbala. They are later released and allowed to return to Medina after Yazid begins to fear the backlash as news of the massacre spreads.
Karbala was a watershed for Yazid. The bloodbath at Karbala, the imprisonment of the women and children of the Household of the Prophet, their parading in chains from town to town, and the speeches made by Zaynab, Imam Husayn's sister, all contributed to the end of Yazid's rule and the overthrow of the dynasty Muawiyah founded.
Whilst it would seem that the birth of Shi'a can be linked to the assertion that only 'Ali could succeed Mohammad as Caliph, the tragedy of Karbala revitalised the official Shi'a movement. The tragedy played an enormous role in the galvanising of Shi'a identity. The fate of Imam Husayn was destined to become the most important agent in the propagation and comparatively rapid spread of Shi'a Islam.