The Kharijites were a radical sect that emerged in the early days of Islam, around the 7th century. They initially supported Ali ibn Abi Talib, the fourth caliph, but later broke away due to disagreements over leadership and governance. The Kharijites believed that any Muslim could lead the community, rejecting the idea of hereditary rule. Known for their strict interpretation of Islam, the Kharijites emphasized piety and moral purity. They were involved in several conflicts, including the Battle of Nahrawan, where they fought against Ali's forces. Their ideology has influenced various Islamic movements throughout history.