According to most reports Husayn b. ‘Ali was born on 5 Sha‘ban 4/10 January 626 CE; another report mentions the middle of Jomada al-awwal 6/beginning of October 627 CE as his date of birth. Jointly with his brother, he was at first brought up in the household of Muhammad.
Many of the accounts about Prophet Muhammad’s treatment of his grandsons and his great love for them deal with them together and at times confuse them. As the elder grandson, Hasan seems to have attracted more attention, and he later remembered more of his grandfather. Husayn is described as looking like Muhammad, but less so than Hasan did.
A leading contemporary Islamicist, Wilferd Madelung has made significant contributions to modern scholarship on mediaeval Islamic communities and movements, including Twelver Shi'ism, Zaydism and Ismailism.