There is no doubt that Imam Ali (a.s) is a figure held in high esteem by all Muslims. He is recognised as being the earliest Muslim, accepting the message of Islam immediately after the first revelation. He is also recognised for his bravery on the battlefront of Islam during the Prophet’s lifetime as well as displaying his wisdom in applying religious judgements.
Despite universal recognition of Imam Ali (a.s) by all Muslims, Imam Ali (a.s) forms a key role in the distinct shaping of a separate and unique Shi’a identity. Due to the fact that Imam Ali (a.s) is recognised by Shi’a as the divinely appointed leader of the Muslims, who immediately succeeded the Prophet; Shi’a have often affirmed their identity upon the point that historically, Imam Ali (a.s) was deprived of this right to rule and hence he and his followers were oppressed in this sense from an early period in Islamic history.
Throughout history the Shi'a have faced oppression for their beliefs, an example is during the ruling period of the Umayyad Dynasty - Imam Ali (a.s) was cursed and maligned from the pulpits and anyone who identified themselves with him were oppressed to the point of execution for merely narrating traditions from Imam Ali (a.s) at this crucial period.