Ibadism is a distinct school of Islam and is commonly regarded as the third Islamic branch, alongside Sunni Islam and Shia Islam. Its roots go back to the Kharijite secession from Ali, the prophet Muhammad's cousin and son in law who was the first Shia Imam and the fourth Sunni Rashidun caliph. Ibadism emerged during the early centuries of Islamic history and developed from the political and theological disputes surrounding the First Fitna. The tradition is historically associated with the early Muhakkima movement, although contemporary Ibadis generally reject the characterization of their faith as Kharijites.