(born 624, Arabia — died 680, Medina) Grandson of
Muhammad, the elder son of Muhammad's daughter
Fatimah. He is one of the five most revered persons in the
Shi'ite branch of
Islam. After the murder of his father,
'Ali, in 661, he was seen by many as the Prophet's rightful heir. When
Mu'awiyah I opposed
Hasan's succession and began to prepare for war,
Hasan raised an army to meet him. Plagued by defections, however, he opened peace negotiations within the year and abandoned the caliphate to his opponent. For the rest of his life he lived quietly in Medina.
For more information on Hasan, visit Britannica.com.