Decline and modernization of the Ottoman Empire
Beginning from the late eighteenth century, the Ottoman Empire faced challenges defending itself against foreign invasion and occupation. In response to foreign threats, the empire initiated a period of tremendous internal reform which came to be known as the Tanzimat, which succeeded in significantly strengthening the Ottoman central state, despite the empire's precarious international position. Over the course of the nineteenth century, the Ottoman state became increasingly powerful and rationalized, exercising a greater degree of influence over its population than in any previous era. The process of reform and modernization in the empire began with the declaration of the Nizam-ı Cedid (New Order) during the reign of Sultan Selim III and was punctuated by several reform decrees, such as the Hatt-ı Şerif of Gülhane in 1839 and the Hatt-ı Hümayun in 1856. At the end of this period, marked with 1908, to a degree the Ottoman military became modernized and professionalized according to the model of Western European Armies. The period was followed by the defeat and dissolution of the Ottoman Empire (1908–1922).
Abolition of the Ottoman sultanate
The Ottoman Dynasty embodied the Ottoman Caliphate since the fourteenth century, starting with the reign of Murad I. The Ottoman Dynasty kept the title Caliph, power over all Muslims, as Mehmed's cousin Abdülmecid II took the title. The Ottoman Dynasty left as a political and religious successor to Muhammad and a leader of the entire Muslim community without borders in a post Ottoman Empire. Abdülmecid II's title was challenged in 1916 by the leader of the Arab Revolt King Hussein bin Ali of Hejaz, who denounced Mehmet V, but his kingdom was defeated and annexed by Ibn Saud in 1925.