The Umayyad tradition of cursing Ali was performed in state-controlled mosques from 657 to 717 CE.

Muawiyah I

Muawiyah I

Muawiyah I was the first Caliph of the Umayyad Dynasty. After the conquest of Mecca by the Muslims, Muawiyah's family converted to Islam. Muawiyah is brother-in-law to Muhammad who married his sister Ramlah bint Abi-Sufyan in 1AH...

, after the stalemate of the Battle of Siffin

Battle of Siffin

The Battle of Siffin occurred during the First Fitna, or first Muslim civil war, with the main engagement taking place from July 26 to July 28. It was fought between Ali ibn Abi Talib and Muawiyah I, on the banks of the Euphrates river, in what is now Ar-Raqqah, Syria...

, began the custom of including a curse against Ali

Ali

' |Ramaḍān]], 40 AH; approximately October 23, 598 or 600 or March 17, 599 – January 27, 661).His father's name was Abu Talib. Ali was also the cousin and son-in-law of the Islamic prophet Muhammad, and ruled over the Islamic Caliphate from 656 to 661, and was the first male convert to Islam...

 from the pulpit in Damascus

Damascus

Damascus , commonly known in Syria as Al Sham , and as the City of Jasmine , is the capital and the second largest city of Syria after Aleppo, both are part of the country's 14 governorates. In addition to being one of the oldest continuously inhabited cities in the world, Damascus is a major...

. As he consolidated his position he mandated this "through all the west" ("while in the east and in al-Kufa they cursed Muawiyah").

People who chose death over cursing Ali

Ali

' |Ramaḍān]], 40 AH; approximately October 23, 598 or 600 or March 17, 599 – January 27, 661).His father's name was Abu Talib. Ali was also the cousin and son-in-law of the Islamic prophet Muhammad, and ruled over the Islamic Caliphate from 656 to 661, and was the first male convert to Islam...

 include:

• Atiyya ibn Sa'd
• Hujr ibn Adi
  Hujr ibn Adi
  Hujr ibn Adi was a supporter of Ali ibn Abi talib, he and his companions were killed by Muawiya I for refusing to Curse Ali. Hujr asked that his son be killed before he did so that he will be sure that his son stayed on the love of Ali and will not be affected by his death.-Character and...
  
  

Umar II

Umar II

Umar ibn Abd al-Aziz was an Umayyad caliph who ruled from 717 to 720. He was also a cousin of the former caliph, being the son of Abd al-Malik's younger brother, Abd al-Aziz. He was also a great-grandson of the companion of the Prophet Muhammad, Umar bin Al-Khattab.-Lineage:Umar was born around...

 put an end to the practice.

Hadith

Several hadiths recall the practice under Muawiyah:

reported similarly:
writes:
The hadiths also recall that the practice continued under the sons of Marwan:
The future Umar II was Marwan's grandson and governed Medina 706-12 CE.

Sunni Denials

Some Sunnis have historically denied that the Umayyads cursed `Ali. Imam al-Nawawi: "The ulamas said: Any hadith that appear to refer to intra-Sahaba enmity is interpreted figuratively. In this hadith [Muslim 31.5915] there is nothing that states that Mu`awiya actually ordered Sa`d to curse `Ali, but he only asked him for the reason why he refrained from cursing him: was it Godwariness? in which case, well done; or fear? etc. It may be that Sa`d was observed among a group that cursed `Ali, but he himself abstained from it although unable to reprimand them, then they were subsequently reprimanded, and Mu`awiya asked him this question. Another possible interpretation is: What prevented you from proving `Ali wrong in his opinion and ijtihad, and tell people the rightness and correctness of our position and ijtihad?"

These denials, in light of the Sunni witnesses and also the Christian witnesses, are dismissed by Western scholars and Shi`ites.