Caliphate

Muhammad (623-632)
Abu Bakr (632-634) father-in-law (Arabic, khalifah, [successor]), khalifat Rasul Allah, [successor to the Messenger of God]), 1st Caliph
Umar I (634-644) amir-al-mum-inin (Arabic, [commander of the believers], 2nd Caliph
Uthman ibn Affan (644-656) Muhammad’s son-in-law, 3rd Caliph
Ali Ben Abu Talib (656-661) a cousin and so n -in-law of Muhammad, 4th Caliph

cont’d

source: http://mb-soft.com/believe/txh/calip00.htm