Karbala’s prominence in Shia traditions is the result of the Battle of Karbala, fought on the site of the modern city on October 10, 680 AD (10 Muharram 61 AH). Both Imam Hussein ibn Ali and his brother Abbas ibn Ali were buried by the local Banī Asad tribe, at what later became known as the Mashhad Al-Hussein. The battle itself occurred as a result of Husain’s refusal of Yazid I‘s demand for allegiance to his caliphate. The Kufan governor, Ubaydallah ibn Ziyad, sent thousands of horsemen against Imam Hussein as he traveled to Kufa. The horsemen, under ‘Umar ibn Sa’d, were ordered to deny Imam Hussein and his followers water in order to force Imam Hussein to agree to give an oath of allegiance. On the 9th of Muharram, Imam Hussein refused, and asked to be given the night to pray. On 10 Muharram, Imam Hussein ibn Ali prayed the morning prayer and led his troops into battle along with his brother Al-Abbas. Many of Hussein’s followers, including all of his present sons Ali al-Akbar, Ali al-Asghar (a few months old) and his nephews Qassim, Aun and Muhammad were killed.
In 63 AH (682 AD), Yazid ibn Mu’awiya released the surviving members of Imam Hussein’s family from prison. On their way to the Mecca, they stopped at the site of the battle. There is record of Sulayman ibn Surad going on pilgrimage to the site as early as 65 AH (685 CE). The city began as a tomb and shrine to Hussein and grew as a city in order to meet the needs of pilgrims. The city and tombs were greatly expanded by successive Muslim rulers, but suffered repeated destruction from attacking armies. The original shrine was destroyed by the Abbasid Caliph Al-Mutawakkil in 850 but was rebuilt in its present form around 979, only to be partly destroyed by fire in 1086 and rebuilt yet again.