Alevism is a sect of Islam which originated in Twelver Shia Islam. Its adherents follow the mystical teachings of Ali, the Twelve Imams, and the 13th-century Alevi saint Haji Bektash Veli. The name "Alevi" originally referred to those who sided with Ali during the succession dispute following Muhammad's death in 632, but the faith deviated from Islam, incorporating 14th century Turkish animism, Shi'ism, and Sufism into its doctrines. By 2017, Alevis made up 10-25% of Turkey's population.