From WikiAhmadiyya, the free encyclopedia on Islam and Ahmadiyyat

Imam Hassan bin Alira also sometimes known as Hasan (625–670) was the grandson and companion of the Prophet of Islam, Muhammadsa and the son of the fourth Caliph, Ali.

Hassan was born to Muhammad'ssa daughter Fatima and her husband Ali. On the death of Ali, Hassan was elected the leader of the Muslims. However his rule was not acknowledged by Mauwiyah and his followers. For a number of months negotiations followed and to prevent a bloody civil war between the Muslims, Hassan abdicated his claim to leadership and instead acknowledged Mauwiyah. Hassan was still a young man - much younger than Mauwiyah - and viewed by much of the general public as the rightful heir on Mawiyah's death. For this reason, those who desired to ascend to power appear to have Hassan assasinated in 670. 

Ahmadiyya view

Hazrat Hussainra was pure himself and also had the capacity to purify others, and, no doubt, he was amongst Chosen Ones whom Allah purifies Himself and fills with His love. He was no doubt among the leaders of the inmates of Paradise

Hazrat Mirza Ghulam Ahmad, Tabligh-e-Risalat

See also