Khilafat political institution established in the Islamic state after the death of Prophet hazrat muhammad (Sm). Khalifah was the head of Muslim state and leader of the Muslim Ummah. The Khalifah was nominated as the protector, the supreme judge and the chief organiser and administrator of the early Islamic state and society. He was the commander of the faithful (Amir-ul-Muminin). xariah law (the quran and Sunnah) limited his authority, but he was the interpreter of the Quran and Sunnah and it was his duty to enforce the provisions contained in them.
Khilafat-e-Rashida continued for about thirty years. Later, the Umayyads took over power. With the fall of the Umayyads two rival Khilafats were established, one by the Abbasids in Baghdad and the other by the Umayyads in Spain. Later, a Fatimid Khilafat was also established. In the eastern lands of Islam where Sunni Muslims were predominant, the Abbasid Khalifah, was considered to be the supreme legal authority. No Muslim kingdom was considered to be legally established, unless it was recognised by the Khalifah.
So the sultans of Delhi and Bengal tried to obtain recognition from the Abbasid Khalifah; sultans Shamsuddin iltutmish, muhammad bin tughlaq and firuz shah tughlaq obtained diploma of investiture, the last two from the Fatimid Khalifahs of Egypt. It is not known whether any Bengal sultan received recognition from the Khalifah, but some of them inscribed the names of Abbasid Khalifahs in their coins, some inscribed epithets owing allegiance to the Khalifah, without mentioning the name. Later some sultans of Bengal beginning from sikandar shah (1357-1384) assumed the title of Khalifah for themselves, that is to say they established a Khilafat in Bengal. [Abdul Karim]
Bibliography TW Arnold, The Caliphate, OUP, Pakistan Branch, 1966; IH Quraishi, Administration of the Sultanate of Delhi, 5th revised edition, 1971; Abdul Karim, Social History of the Muslims in Bengal, 2nd edition, Chittagong, 1985.