1. In the Qurʾān, frequently used of those who enter into the blessings enjoyed by their ancestors (e.g. 6. 165; 24. 55; 27. 62); and specifically of Adam as khalīfat Allāh on earth (2. 20).
2. The successor(s) of the Prophet Muḥammad. The first three Khulafāʾ were Abu Bakr, ʿUmar, and ʿUthmān. But some thought that ʿAlī, Muḥammad's nearest male relative, should have succeeded, and become the party (shīʿa) of ʿAli. His claim prevailed briefly, and he was the fourth caliph; but other dynasties, ʿUmayyad (661–750 CE), then ʿAbbasid (750–1517) were established, and the Shīʿa became minorities with their own rulers and successions (see IMĀM). The first four khulafāʾ are known as arRāshidūn, the upright or rightly guided. The Caliphate was assumed by the Ottoman Turkish rulers (sultāns) as a title, and it was abolished in the secularizing reforms of Kemal Atatürk in 1924.
"Khalīfa." The Concise Oxford Dictionary of World Religions. . Encyclopedia.com. (May 22, 2018). http://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/khalifa
"Khalīfa." The Concise Oxford Dictionary of World Religions. . Retrieved May 22, 2018 from Encyclopedia.com: http://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/khalifa