 Imam Husain's son, Imam Ali ibn Husain, was imprisoned along with Husain's sister and other ladies left in Karbala war.Due to opposition by public they were later released and allowed to go to their native place Medina.One Imam after another continued in the generation of Imam Husain but they were opposed by the Caliphs of the day as their rivals till Imam Abdullah al-Mahdi Billah came in power as first Caliph of Fatimid in North Africa when Caliphate and Imamate came to same person again after Imam Ali.