With the establishments of Sufi orders like the Bayramiyya and Mawlawiyya under the Ottoman Caliphate, the mystical side of Islam, Sufism, flourished.

[8] Prior to 1517, Selim I had ordered that the khutbah be recited in his name as Ottoman caliph several times, for instance at Tabriz in 1514 and at Aleppo in 1516.

[7] The conquest of Egypt made the Ottoman Empire one of the largest states in the world, and it had also gained control of Mecca and Medina, the religious and cultural centers of Islam.

[7] A contradictory story, likewise without contemporary evidence and thus questioned by historians, claims that al-Mutawakkil instead transferred the title of caliph to Suleiman I in 1538.

[7] No ceremony of this kind had ever taken place prior to Selim[7] and given that al-Mutawakkil did not possess any real religious authority, he would not have been able to transfer anything significant to the sultan.

[7] At the height of its power in the 16th–17th centuries, the Ottoman Empire spanned three continents, controlling parts of Southeastern Europe, the Middle East and most of North Africa.

[8] The Ottoman jurist Ebussuud Efendi called both Suleiman and his son Selim II (r. 1566–1574) "caliph to the apostle of the lord of the worlds".

[17] In the Treaty of Küçük Kaynarca (21 July 1774), the Russian Empire thus recognized the Ottoman sultan as the "Supreme Muhammedan Caliph"[12] and as the religious leaders of the Muslim Crimean Tatars.

[22] Religious conflict and conflict with various Western powers plagued much of Abdul Hamid's first two decades on the throne, including massive interreligious violence in the Balkans after the conclusion of the Russo-Turkish War, Austro-Hungarian occupation of Bosnia in 1878, British occupation of Egypt in 1882, large massacres of Armenian Christians in 1894–1897, and war with Greece in 1897.

[23][24] In light of these developments, the greatest attempt to revive classical idea of the caliph as both the religious and political leader of the Muslim ummah occurred in Abdul Hamid's reign.

[25] By emphasizing his position as caliph, Abdul Hamid could continue to claim religious authority over the Muslims who lived in territories the empire had lost, such as in the Balkans and North Africa.

[22] Abdul Hamid's personal popularity was further increased through the construction of the Hejaz railway (completed in 1900), which made pilgrimage significantly cheaper, quicker, and easier.

[25] Western authorities in Britain, France, Russia, and the Netherlands were anxious over Abdul Hamid's policies due to the sultan's great popularity among the Muslims in their colonies, worried that he might inspire an anti-colonial jihad.

[28][29] A decisive point in the weakening of the Ottoman Empire as a world power was the Young Turk Revolution of 1908,[30] which established a constitutional government under the Committee of Union and Progress (CUP).

[30] The CUP realized that the cliphate as an office had great international prestige and potential power in gaining support from Muslims abroad and thus sought to preserve the institution.

[31] In 1909, there was a failed counter-revolution (the so-called 31 March incident)[27] which to CUP officials demonstrated that the Ottomans were not ready to adapt to the new political system.

[15] Pro-Ottoman writers, who included numerous Arab traditionalists, perceived questions of the Ottoman Caliphate's legitimacy as a threat to Muslim unity.

[15] Britain encouraged Hussein bin Ali al-Hashimi, the Sharif of Mecca, to rebel against the Ottoman Empire, promising him both independence and the creation of an Arab nation-state.

Muslims worldwide were forced into the unprecedented position of having to choose between loyalty to the Ottoman caliph, their symbolic religious leader, or the Sharif of Mecca, the spiritial and political head of Islam's holiest city.

Shortly after the war's end, Greece was allowed by the Entente to occupy the strategic port of Smyrna and the surrounding territories, provoking widespread outrage in the Ottoman Empire.

[38] The nationalists asserted to the government that "the nation has no confidence left in any of you other than the sultan", ostensibly seeking to "free" Mehmed from foreign occupation and his "collaborationist" officials.

The treaty confirmed the loss of all Arab provinces, the creation of autonomous territories for Kurds and Armenians, the transfer of large parts of the Mediterranean coastline to France and Italy, and Greek autonomy in the Smyrna region and East Thrace.

On 1 November 1922, Mustafa Kemal Pasha, later called Atatürk ("father of the Turks"), submitted a motion to the Grand National Assembly to strip the sultan and the Ottoman government of all political power.

[36] Sixteen days later, Mehmed's continued nominal tenure as caliph likewise came to an end as he was taken out of Constantinople in exile aboard a British warship.

[43][44] The movement was undermined through the Ottoman defeat in the Turkish War of Independence and the deposition of Mehmed VI, and finally collapsed when the caliphate was abolished in 1924.

[40] After Mehmed VI's deposition and exile, the Grand National Assembly elected his cousin Abdülmecid II as caliph on 19 November 1922.

[36] Abdülmecid at one point requested the government for an increase of his allowance, which prompted Atatürk to write to him: "Your office, the caliphate, is nothing more than a historic relic.

"[45] In 1923, the Indian Muslim scholar Syed Ameer Ali wrote a public letter to the Turkish government to implore them to restore the authority of the Ottoman caliph.

Such a congress was held in May 1926, with delegates from Egypt, India, Indonesia, Iraq, Malaysia, Morocco, Poland, South Africa, and Yemen.

Atatürk however questioned whether it would be rational or logical to entrust the management of the entire Muslim world's problems to a single state or individual.