Characteristics of Imam Hasan http://www.tebyan.net/english/Events/2003/07/Html/imam-askari.htm http://www.tebyan.net/english/IslamicInformations/etr/etr4/etr4_right.htm The Peace Treaty between Imam Hasan and Mu'awiya
Some criticize the Shi'as saying that Imam Hasan had made peace with Mu'awiya (the first Umayyad caliph) and put an end to the conflict between them, and that he did not listen to his Companions who wanted instead to involve him in sedition. To them this indicates that the policy of the Prophet's family towards his Companions was not a hostile policy at all as the Shia claim.THE ANSWER
When Imam Hasan bin Ali set about making peace with Mu'awiya and ending the war with him, he was not going against the policy of his father (Imam Ali). Imam Hasan's army by that time had become weak, discord had erupted within the ranks, and many of them refused to obey him. Many men were overcome by greed and sided with Mu'awiya. Imam Hasan (a) knew that the war with Mu'awiya would not be for his benefit and it would cause the shedding of Muslim blood and the killing of the followers of the Prophet's family; therefore, he was obliged to make peace with Mu'awiya in order to spare their blood.
However Imam Hasan was never agreeable with Mu'awiya being the caliph of the Muslims. His exalted personality could never have accepted such a claim. Anyone who knows anything about the circumstances of the peace treaty between Imam Hasan and Mu'awiya would be certain that Imam Hasan, his father, and his brother (Imam Hossein) thought that Mu'awiya and all the Umayyads were of the same ilk without any difference.