Ali ibn Abi Talib served as the fourth caliph of the Rashidun Caliphate, which was noted for its rapid territorial expansion and establishment of Islamic governance in the early years of Islam. His caliphate was marred by ongoing discord and civil war, notably the First Fitna, which pitted him against significant opponents such as Muawiya, the governor of Syria. Despite numerous attempts at finding a resolution through negotiation, tensions escalated, leading to an inevitable clash of ambitions. On this catastrophic day in Kufa, while leading prayers, Ali was attacked by a member of the Kharijites, a faction that had once fought under him but had since turned against him, believing he had compromised Islamic principles in the pursuit of power. A poisoned sword inflicted severe injuries that ultimately resulted in his death two days later.

The assassination of Ali dramatically impacted the Islamic political landscape. It not only ended the Rashidun Caliphate but also initiated a prolonged period of contention regarding rightful leadership among Muslims. Following Ali's death, his son, Hasan, briefly succeeded him but later abdicated in favor of Muawiya, who would establish the Umayyad dynasty. This shift in power marked the commencement of a line of dominion that sought to consolidate and expand Islamic rule, but also laid grounds for future sectarian discord that would spawn the Sunni-Shia divide, a lasting schism within Islamic communities.

Ali’s legacy as the 'Commander of the Faithful' and a paragon of virtue and justice continued posthumously in both Sunni and Shia Islam. The reverence for his principles and actions remains a foundational aspect of Islamic heritage, with both sects acknowledging his significant contributions. His assassination is viewed by many as a crucial turning point in Islamic history, leading to questions of legitimacy, governance, and religious authority that have influenced Islamic thought and politics through the centuries.