Umar (/ˈuːmɑːr/), also spelled Omar (/ˈoʊmɑːr/; Arabic: عمر بن الخطاب ʻUmar ibn al-Khaṭṭāb [ˈʕomɑr-, ˈʕʊmɑr ɪbn alxɑtˤˈtˤɑːb], "Umar, Son of , was one of the most powerful and influential Muslim caliphs in history. He was a senior companion of the Prophet Muhammad. He succeeded Abu Bakr (632–634) as the second caliph of the Rashidun Caliphate on 23 August 634.
