The main line of Sunni Caliphs – Rightly Guided, then Umayyad, then Abbasid – came to an end when the Mongols conquered Baghdad in 1258.
A surviving member of the Abbasid house was installed at Cairo under the patronage of the newly formed Mamluk Sultanate three years later.
In 1517 the Ottoman Turks took the last nominal Abbasid Caliph at Cairo into custody and transported him to Constantinople.
When he died, the Caliphate was virtually in abeyance. The first time Caliph was used as a political instead of symbolic religious title by the Ottoman Sultans was in the peace treaty with Russia at the end of the war of 1768-74, as a way of allowing the Turks to retain moral authority in territory they had ceded, notably the Crimea.
Around 1880 Sultan Abdul Hamid II reasserted the title as Russian expanded into Central Asia. His claim was most fervently accepted by the Muslims of British India.
The Khilafat movement (1919-24) was a vain pan-Islamic protest campaign launched by Muslims in India to persuade the British government to protect the Ottoman Empire and the Caliphate. The Ottoman Sultanate was abolished in 1922, the Caliphate in 1924.
At the time when the present chapter was being written, it looked as if this had really been the end of the Caliphate, for an immediate attempt on the part of the Hāshimī King Husayn of the Hijāz to assume the office (on the eve, as it turned out, of his own ejection from his ancestral patrimony by Ibn Saʿūd) was – in spite of the Sharīf’s unimpeachable Qurayshī lineage and his sovereignty, at the moment, over the two Holy Cities of Mecca and Medina – as dismal a failure as most of his other enterprises. Nor did any practical action result from a Caliphate Congress held at Cairo on the 13th-19th May, 1926.
Yet, even if this forecast were to prove correct – though, in the light of previous history, it would not be safe to sign a death certificate for so resilient an institution as the Caliphate until it had been in abeyance for at least a quarter of a millennium [footnote: Its latest interregnum had lasted from the death of the last Cairene ʿAbbasid Caliph Mutawakkil in A.D. 1543 to the drafting of the Russo-Turkish Treaty of Küchuk Qaynārja in A.D. 1774.] – the marvel would be, not that the Caliphate should have petered out at last, but that, on the strength of having been an effective sovereignty over a span of less than two hundred years, [footnote: From the death of the Prophet Muhammad in A.D. 632 to the death of the ʿAbbasid Caliph Amīn (imperabat A.D. 809-13), in a civil war with his brother and supplanter Ma’mūn (imperabat A.D. 813-33) over the heritage of their father Hārūn-ar-Rashīd (imperabat A.D. 786-809).] it should have been able within that time to acquire a prestige sufficient to keep it alive, and twice revive it, [footnote: i.e. at Cairo in A.D. 1261 and at Constantinople in A.D. 1774.] for another eleven hundred years [footnote: Reckoning from the death of the Baghdādi ʿAbbasid Caliph Amīn in A.D. 813 to the deposition of the Constantinopolitan ʿOsmanli Caliph ʿAbd-al-Mejīd in A.D. 1924.] during which it never emerged from the state of political impotence into which it had begun to decline in the reign of Hārūn-ar-Rashīd’s son Ma’mūn (imperabat A.D. 813-33).
The revival of the Caliphate is often predicted today, in Brummie, Indonesian and other accents.
Ma’mūn is written thus in the OUP text, not as Maʿmūn.
At times in Muslim history there have been rival caliphs, notably those of the Ismaili Shia Fatimid Caliphate in North Africa, 909-1171.
A Study of History, Vol VII, OUP, 1954