Final answer:
The divide between Sunni and Shia Muslims originated from the historical event known as the First Fitna, which was a civil war between Muslims that occurred in 657.
This succession dispute and the conflicts that followed led to the split between the two branches of Islam.
Step-by-step explanation:
The divide between Sunni Muslims and Shia Muslims originated from a historical event known as the First Fitna, which was a civil war between Muslims that broke out in 657.
The conflict began after the assassination of Uthman, the third caliph, and resulted in Ali, Muhammad's son-in-law, becoming the new leader.
However, his rule was undermined by continuous conflicts and eventually led to his assassination. This succession dispute and the subsequent conflicts led to the split between Sunni and Shia Muslims.