Why did shite and sunni split?

The split between Shia and Sunni Islam originated from a dispute over the rightful successor to the Prophet Muhammad after his death in 632 CE. Sunni Muslims believed that the community should choose the leader (caliph), leading to the selection of Abu Bakr, while Shia Muslims argued that leadership should remain within the Prophet's family, specifically favoring Ali, his cousin and son-in-law. This theological and political disagreement eventually evolved into distinct religious identities, with differing beliefs, practices, and interpretations of Islam. Over time, historical events and power struggles further deepened the divide between the two sects.