Sunni Islam accepts the legitimacy of the incoming caliph by relying on the oath of the previous caliph. However, the caliphate and Imamate of the previous caliph must indisputably be proven before his oath can be considered valid. In Mu‘awiyah’s case, this was not so. His caliphate was never proven legitimate, as the following information shows:
Firstly, Mu‘awiyah gained control of the caliphate and predominance over the Islamic community by rebelling against the rightful Imam of the Muslims, Amir al-Mu’minin Imam ‘Ali ibn Abi Talib (as). Therefore, Mu‘awiyah’s caliphate itself lacked legitimacy and was void of any reasonable religious or legal base.
Secondly, in Imam al-Hasan’s (as) peace agreement, it was stated that the tax, revenue and tribute of Abjard must be handed over to Imam al-Hasan (as). This confirms that Imam al-Hasan (as) did not recognize Mu‘awiyah as the rightful caliph of the Muslims. The reason is that the area of Abjard had come under the fold of Islam peacefully, and had not been conquered by force or the strength of an army.
According to the Islamic law, the tax from this kind of place is exclusively reserved for the legitimate Imam of the Muslims. Therefore, Imam al-Hasan (as), who was the legitimate Imam of the Muslims, demanded this share and allotment in his agreement with Mu‘awiyah.27
Thirdly, one of the conditions that Imam al-Hasan (as) included in the peace pact was that Mu‘awiyah would have to abstain from calling himself amir al-mu’minin (the Commander of the Faithful). This is a clear declaration from Imam al-Hasan (as) that he did not in reality support or endorse the legitimacy of the government of Mu‘awiyah, the son of Abu Sufiyan.
Firstly, in a letter to his governor of Medina, Yazid wrote, “You must secure the allegiance of individuals who enjoy special honor and status among the people by whatever means there are at your disposal; secure the allegiance of such people as al-Husayn ibn ‘Ali, ‘Abd Allah ibn ‘Umar, ‘Abd al-Rahman ibn Abi Bakr and ‘Abd Allah ibn Zubayr.
If they refuse to pay allegiance, kill them.”28 Of course, it must be pointed out that allegiance that is paid reluctantly or out of coercion is not considered to be legitimate or valid at all.
Secondly, the people of Iraq had written a letter to Imam al-Husayn ibn ‘Ali (as) in which they manifestly declared that they did not have an imam and were not going to pay allegiance to anyone save al-Husayn ibn ‘Ali (as).29
Thirdly, Shabrawi Shafi‘i strongly opposes any defence of Yazid’s caliphate by certain scholars. First, he quotes and recounts the reasons which have been put forward by Ghazzali and Ibn al-‘Arabi as their legal bases and reasons for prohibiting cursing or reviling Yazid.
Then, he gives a detailed account of the overstatements of these two people regarding the issue of cursing Yazid. He says, “The statements of Ghazzali and Ibn al-‘Arabi are false, because they are founded on the assumption that the allegiance paid to Yazid—Allah’s curse be on him—was correct and sound, in spite of the fact that this view is opposed by historians.”30
27. Futuh al-Buldan, p. 380.
28. Al-Futuh, vol. 5, pp. 10-11; Tarikh Ya‘qubi, vol. 2, p. 241.
29. Al-Bidayah wa al-Nihayah, vol. 8, pp. 151-152.
30. Al-Ithaf bi Hubb al-Ashraf, p. 68.
Adapted from: "The Uprising of Ashura and Responses to Doubts" by: "‘Ali Asghar Ridwani"