Abu Muhammad Hasan, or Hasan (Handsome), the elder brother of Hussain was born in 3/625 in Medina. He was also brought up with Hussain in the household of Muhammad until the latter's death when Hasan was about 7 years old. It emerges from the extant traditions that Muhammad had a great fondness for his two grand-children. Hasan and Hussain, whom he referred to as the "chief of the youths of paradise." Another tradition relates, "Both Hasan and Hussain are for me the fragrance in the world."
Hasan was 37 years old when his father fell at the hands of the assassin at Kufa. Qais bin Sa'd was the first to swear allegiance to Hasan on the day when Ali died, and then it was followed by 40,000 Kufans, acclaiming Hasan as the fifth caliph. Tabari (2nd vol., p. 5) writes that the oath of allegiance taken by those present stipulated that, "They should make war on those who were at war with Hasan, and should live in peace with those who were at peace with Hasan." This sharply suggests that the oath sworn by the Kufans was purely political. Thus, as we have discussed, the temporal power that had been with Muhammad, had joined with the caliphate of Ali about 24 years, 8 months and 28 days after the death of Muhammad. When Ali died, the same powers, though remained with the Ahl-al-Bait, were separated once again. The temporal authority had gone to the hands of Hasan, and the spiritual authority was inherited by Hussain and in his Hussainid progeny.
Hasan's acclamation as caliph by the Kufans was a great cause of alarm to Muawiya, who had been working for the office since the death of Uthman. He dispatched many of his agents and spies to arouse the people against Hasan in Yamen, Hijaz, Iran and Iraq. At length, he began preparations for war and summoned all the commanders of his forces in Syria, Palestine and Trans-Jordan to join him. Not longer after, the Syrian leaders marched against Hasan with an army of 60,000 men. Muawiya's purpose of this prompt action was twofold. Firstly, by demonstration of arms and strength, he intended to force Hasan to come to terms; and secondly, if that course of action failed, he would attack the Kufan forces before they had time to consolidate their position. It was for the first reason that Muawiya moved towards Iraq at a very slow pace, while sending letter after letter to Hasan, asking him not to try to fight and urging him to come to terms. If Hasan was defeated, this would give Muawiya only power and authority; but if Hasan abdicated, this would provide Muawiya with a legal base and legitimize his authority as well. This was what Muawiya was actually trying to achieve.
Soon after, Hasan left Kufa with his main force and reached Madain, where he pitched his camp in the outskirts of the city. Qais bin Sa'd and his vanguard had already reached Maskin, facing Muawiya's army. The Syrian governor tried to bribe Qais by offering him a million dhirams if he would defect from the ranks of Hasan and join him. Yaqubi (2nd vol., p. 214) writes that Qais rejected the offer, saying: "You want to deceive me in my religion." Muawiya then made a similar offer to Ubaidullah bin Abbas, who accepted it and went over to him with 8000 soldiers. Qais was thus left only 4000 soldiers, waiting at Maskin for the arrival of Hasan.
While Hasan himself faced a serious situation at Madain. Some of his troops hatched rebellion against him, plundered his tent, and fell upon him. Different versions of this rebellion are given in the sources. According to Yaqubi (2nd vol., p. 115), "As soon as Hasan reached Madain, Muawiya sent Mughira bin Shuba, Abdullah bin Amir and Abdur Rahman bin Umm al-Hakama to Hasan as his mediators. After they talked to Hasan privately, and while leaving his camp, they spread the news that Hasan had agreed to relinquish the power in favour of Muawiya, whereupon Hasan's soldiers fell upon him and plundered his tent." Yaqubi also records that Muawiya sent his men to Hasan's camp to spread the news that Qais had made peace with Muawiya at Maskin and had come over to his side, while simultaneously he spread the rumours in the army of Qais at Maskin that Hasan had made peace with Muawiya. In this case, again, Muawiya's machinations are responsible for the mutiny in Hasan's army. Another reason of rebellion is given by Dinawari (d. 276/889) in his "Kitab al-Akhbar at-Tiwal" (Cairo, 1960, p. 216) that when Hasan left Kufa, he reached Sabat, in the outskirts of Madain, and discerned that some of his troops were showing fickleness, lack of purpose and withdrawn attitude to the war. Hasan therefore halted at Sabat for a while, and made a following speech:-
"O people, I do not entertain any feeling of rancour against a Muslim. I am as much an overseer over yourselves as I am over my own self. Now, I am considering a plan; do not oppose me in it. Reconciliation, disliked by some of you, is better than the split that some of you prefer, especially when I see that most of you are shrinking from the war and are hesitant to fight. I do not, therefore, consider it wise to impose upon you something which you do not like."
When his people heard the above speech, they silently looked at each other, reflecting their suspicions. Dinawari continues to write that those among them who were of Kharijite persuasion said: "Hasan has become infidel as had become his father before him." They suddenly rushed upon him, pulled the carpet from under his feet, and tore his clothes from his shoulder. Hasan called for help from among his faithful followers from the tribes of Rabia and Hamdan, who rushed to his assistance and pushed the assailants away from him. The disheartened and shaken Hasan found it dangerous to stay in the army camp. He rode away with his trusted men towards the White Castle of Madain, the residence of his governor, Sa'd bin Masud. He was however wounded on his way by Jarrah bin Sinan Asadi with a dagger. Hasan, bleeding profusely, was carried to the White Castle, where he was cared for by his governor.
Qais at Maskin was facing Muawiya's army and waiting for Hasan's arrival. When he heard of the attack on Hasan, Qais thought it wise to engage his soldiers in battle with the Syrians, so that they should not have a chance to brood over the situation, and become more demoralized. Thus, an encounter between the two armies took place, resulting some losses on both sides. According to Ibn Atham (d. 314/926) in "Kitab al-Futuh" (4th vol., p. 156), the envoys of Muawiya then came forward in the battlefield and addressed Qais, saying: "For what cause are you now fighting with us and killing yourself? We have received unquestionable word that your leader has been deserted by his people and has been stabbed with a dagger and is on the verge of death. You should therefore refrain from fighting until you get the exact information about the situation." Hence, Qais was forced to stop fighting and had to wait for the official news about the incident from Hasan himself. But by this time, his soldiers began defecting to Muawiya in large number. When Qais noticed this large scale desertion, he wrote to Hasan about the gravity of the situation. When Hasan received the letter from Qais, he lost his heart, and immediately summoned the Iraqi leaders and nobles and addressed them, according to Ibn Atham (4th vol., p. 157) in dejection and disgust as under:-
"O people of Iraq, what should I do with your people who are with me? Here is the letter of Qais bin Sa'd, informing me that even the nobles from among you have gone over to Muawiya. By God, what shocking and abominable behaviour on your part! You were the people who forced my father to accept arbitration at Siffin; and when the arbitration to which he yielded (because of your demand), you turned against him. And when he called upon you to fight Muawiya once again, then you showed your slackness and lassitude. After the death of my father, you yourself came to me and paid me homage out of your own desire and wish. I accepted your homage and came out against Muawiya; only God knows how much I meant to do. Now you are behaving in the same manner as before. O people of Iraq, it would be enough for me from you if you would not defame me in my religion, because now I am going to hand over this affair to Muawiya."
Soon after his plausible speech, Hasan sent word to Muawiya, informing him of his readiness to abdicate the rule. When the news reached to Qais officially, he told to his soldiers that, "Now you must choose between the two, either to fight without a leader or to pay homage to the misled." They replied that, "Paying homage is easier for us than bloodshed." Hence Qais withdrew from the field alongwith those who were still with him, and left Maskin for Kufa.
Hasan sent Abdullah bin Nawfal bin Harith to Muawiya at Maskin for the terms. Hearing this, Muawiya took a blank sheet of paper, affixed his signature and seal, and said to Abdullah to take it to Hasan and ask him to write on it whatever he wanted. Ibn Atham (4th vol., p. 159) writes that when the blank sheet had been presented to Hasan, he called his secretary, and asked him to write: "These are the terms on which Hasan bin Ali bin Abu Talib is making peace with Muawiya bin Abu Sufian, and handing over to him the state or government of Amir al-Mominin Ali:- 1) that Muawiya should rule according to the Book of God, the Sunnah of the Prophet, and the conduct of the righteous caliphs. 2) that Muawiya will not appoint or nominate anyone to the caliphate after him, but the choice will be left to the shuraof the Muslims. 3) that the people will be left in peace wherever they are in the land of God. 4) that the companions and followers of Ali, their lives, properties, their women, and their children, will be guaranteed safe conduct and peace. 5) that no harm or dangerous act, secretly or openly, will be done to Hasan bin Ali, his brother Hussain, or to anyone from the family of the Prophet." This agreement is witnessed by Abdullah bin Nawfal, Umar bin Abu Salama and so and so.
The agreement having been concluded, Hasan returned to Kufa where Qais joined him. Soon afterwards, Muawiya entered the city with the full force of his army. He held a general assembly, and different groups of people, one after the other, paid him homage. The speech of Hasan in Kufa delivered at the insistence of Amr bin al-A'as and Muawiya is worth noting. Abul Faraj quotes the speech in his "Maqatil" (p. 72) which reads: "The caliph (khalifa) is one who dedicates himself to the way of God and the Sunnah of His Prophet, and not the one who is an oppressor and aggressor; the latter is only a king (malik) who rules a kingdom (mulk), whose enjoyment is little, and whose pleasure is short-lived, leaving behind only a trace of it. I do not know if this is a trial for you and a grant of livelihood to you for a period." It is interesting to note that if this quotation is historically correct, it might be the origin of the use of the word mulk (king) instead of khalifa (caliph) for Muawiya and his successors, used by the historians from the earliest times. There are however numerous instances, where Muawiya is recorded as saying, in reference to himself, "I am the first king of Islam." (vide "Bidaya wa'n Nihaya" by Ibn Kathir, Cairo, 1939, 8th vol., p. 135). Thus, Muawiya grabbed the power and founded the Umayyad rule in Syria. He lived on a scale of royal splendour comparable only to the pomp and pageantry of the Byzantine emperors.
The extant sources specify the causes of Hasan's renunciation as love for peace, distaste for politics and its dissensions, and the desire to avoid widespread bloodshed among the Muslims. He relinquished the power in 41/661 after ruling for 6 months and 3 days, and the year of his abdication became known as the "Year of the Community" (am al-jama'a). Tabari (2nd vol., p. 199) quotes a tradition to this effect, attributed to the Prophet, who is reported as saying: "This son of mine is a lord (sayed) and he will unite two branches of the Muslims."
Hasan had certainly prevented a bloody military solution of the conflict by abdicating in favour of Muawiya. His abdication had far-reaching consequences for the later development of Shiism. Now the wheel turned on reverse side, as the Uthmaniya branch, with Muawiya its head, became the central body, while the Shiat-i Ali was reduced to the role of a small opposition party.
Hasan, after his abdication in 41/661, quitted Kufa and retired to Medina and led a quiet life. His attitude could be understood from the fact that during his journey back to Medina, at Qadisiya, according to Baladhuri (d. 279/892) in "Ansab al- Ashraf" (ed. M. Hamidullah, Cairo, 1955, 4th vol., p. 138), he received a letter from Muawiya, asking him to take part in a campaign against a Khariji revolt which had just erupted. Hasan replied that he had given up fighting in order to restore peace, and that he would not take part in a campaign at his side.
Muawiya's ambitious plans to perpetuate the caliphate in his own house and nominate his son Yazid as his heir-apparent, were not so possible, because of the terms on which Hasan had abdicated to Muawiya. To carry out his plan, Muawiya had to remove Hasan from the scene. The sources admit that the cause of Hasan's death was poison administered by one of his wives, Juda bint al-Ash'ath. Muawiya is reported to have suborned her with the promise of a large sum of money and of marrying her to his son Yazid. After she had completed the task, Muawiya paid her the promised sum of money but refused to marry her to Yazid, saying that he valued the life of his son. Thus, the death of Hasan took place in 49/669 at the early age of 46 years.