Imam Hasan assumed the responsibility of the Caliphate after the martyrdom of his father, and the people of Kufa gave him the pledge of fealty. He addressed a large congregation of believers in the mosque and reminded them of the stand his father had taken in upholding the Truth, and that he would not change his course of conduct in any other way. He also reminded them of the deceitful way in which they were deprived of their victory over Muawiyah, the defiant governor of
. He strongly urged them to search their hearts if they wished to achieve a stable and pious way of life under his rule. Syria
Muawiyah continued his unrelenting efforts to weaken the position of Imam Hasan from the seat of Caliphate. The hnam wrote him a letter inviting him for peace, and to join him in furthering the cause of a unified Islamic State. This called for Muawiyah to accept Imam Hasan as the legitimate successor of the Caliphate. Muawiyah had previously declined this in a similar communication from Imam Ali, and had carried arms against him.
Imam Hasan called up his forces from his pledged supporters. However, the army he could gather consisted of people with disparate motives. Although there were some true believers in the army, many others had joined in for the sake of war spoils and with divided loyalties. Thus, even some Kharjites had joined the army, not for the love of the Imam but, in the event of victory, for their own design of eliminating Muawiyah from the Caliphate. There were others who had come, not because they believed in fighting for the cause of the Truth but because their tribal leaders had urged them to do so.
However, just before the impending war, Muawiyah was able to break the strength of the Imams army by paying off some and diverting others away from h4n, and spread the manors that the Imam had agreed to stop the war to save bloodshed of Muslims on either side. These rumors had their desired effect. The Kharjis saw a failure of their own goal through the forces of the Imam, so they turned against him. He received a bad slash on his thigh, and was quickly taken away by his supporters for care and tending. His army dispersed to escape a general massacre by Muawiyah's forces.
The leaders of several tribes wrote to Muawiyah for his clemency towards them in exchange for surrendering Imam Hasan to him. Muawiyah sent all these letter to the Imam and offered him safe passage to Madinah under all the conditions he chose for himself. To this end, he sent Imam Hasan a blank page with his stamps in the bottom of the page. Then Muawiyah wrote, "In this page, whose bottom I have stamped, stipulate whatever you want, for that will be for you."
The Imam, in his desire to avoid bloodshed and to uphold the unity of the Muslim Ummah, saw the advantage in accepting Muawiyah's offer. He was well aware of the ploy of Muawiyah during the days of his father, and he had seen his tactics during the Battle of Siffeen. He had seen Muawiyah's devious means during his confrontation with him, and had seen the rift and loss of life of the Muslims on both sides. The apparent truce was a safe way out from the bitter confrontation. The Imam accepted peace in order to preserve the integrity of Islam. He wrote on the page provided by Muawiyah all the conditions that suited him, his family and towards his role as the Imam of believers. It is unfortunate that this page is not valuable to us. However, the conditions laid down by the Imam have been mentioned in several authoritative works of history and biography.