wikishia:Featured Article/2014/26
Ḥasan b. ʿAlī b. Abī Tālib (a) (حسن بن علی بن ابی طالب) (b.3/625-d.50/670), son of 'Ali (a) and Fatima (s), is the second Imam of Shi'a and came to caliphate and imamate at the age of 37. He accepted a peace treaty with Mu'awiya in 41/661. His government lasted 6 months and 3 days. He went to Medina after accepting the peace treaty, stayed there until he was martyred ten years later and was buried in Jannat al-Baqi' cemetery.
He carried out the two great responsibilities of Imamate and preserving unity of Muslims which led to accepting a peace treaty with Mu'awiya and these roles show a solemn and tolerant personality of him. His caliphate and the peace he made with Mu'awiya are among the most important occasions of his life and the early Islamic history which displayed an example of unity at that time and also as a moral and religious teaching greatly regulated Muslims and especially Shi'a's approach towards fundamental concepts such as authority, war and peace throughout their history.