Final answer:
The death of Caliph Ali led to a division in Islam between Sunni and Shi'a. Sunnis believed any righteous leader could be caliph, while Shi'as believed in the succession through Muhammad's family.
Step-by-step explanation:
The impact of the death of Caliph Ali was that Islam was divided into Sunni and Shi'a over who would be the rightful successor. Ali's followers, who believed he should have succeeded Muhammad directly, became known as the Shi'a. The majority of Muslims, known as Sunnis, believed that any righteous and competent leader could be appointed caliph. This division between Sunni and Shi'a still exists today.