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).
Military of the Ottoman Empire
The history of the military of the Ottoman Empire can be divided in five main periods. The foundation era covers the years between 1300 (Byzantine expedition) and 1453 (Fall of Constantinople), the classical period covers the years between 1451 (enthronement of Sultan Mehmed II) and 1606 (Peace of Zsitvatorok), the reformation period covers the years between 1606 and 1826 (Vaka-i Hayriye), the modernisation period covers the years between 1826 and 1858 and decline period covers the years between 1861 (enthronement of Sultan Abdülaziz) and 1918 (Armistice of Mudros).