Explanation
First Caliph : Hazrat Abu Bakr (June 8, 632 – August 23, 634) Second Caliph: Hazrat Umar (R.A.) Third Caliph : Hazrat Usman (R.A.) Fourth Caliph: Hazrat Ali (R.A.) (656–661 CE) Sahabi who proposed Hazrat Abu Bakr for the Caliphate : Hazrat Umar (R.A.)
