Final answer:
The divide between Shia and Sunni Islam originated from a dispute over the rightful Islamic leadership following the Prophet Muhammad's death, with Shia believing in the Prophet's family lineage while Sunni following the Prophet's customs and broader consensus. This division has deeply influenced Islamic history and politics, notably shaping the civial unrest in Iraq among other regions.
Step-by-step explanation:
The Shia and Sunni divide represents a significant schism within Islamic history. After the death of the Prophet Muhammad, a contentious battle over succession led to the formation of two main branches. The Shia believed that leadership should remain within the Prophet's family through his son-in-law Ali and his descendants.
Conversely, the Sunni Muslims accepted the caliphates of Abu Bakr, Umar, Uthman, and later Ali, focusing on the customs of the Prophet (the sunna) without a requirement for leadership to be Muhammad's direct descendants. This ideological split led to various conflicts and permeated into the political landscapes of Islamic nations, notably contributing to civil unrest in countries like Iraq.
In regions such as Iraq, the majority Shia Arabs have shared a historical struggle against minority Sunni leadership, especially under the rule of Saddam Hussein. The significance of cities like Najaf and Karbala to Shia Muslims and the mourning of events such as the death of Husayn, reinforce the historical and religious depth of the Shia sentiment.
The Sunni, forming the majority of the Muslim world, adhere to a different interpretation of Islam's early succession and religious practice. With time, these differences have been compounded by political, ethnic, and regional factors, sustaining the divide into contemporary times.
Ultimately, as with many religious schisms, the divide between Sunni and Shia has evolved from a question of religious legitimacy into a multifaceted tapestry of historical grievances, cultural identity, and political power dynamics.