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).
History of the Ottoman Empire
The Serbian revolution (1804–1815) marked the beginning of an era of national awakening in the Balkans during the Eastern Question. Suzerainty of Serbia as a hereditary monarchy under its own dynasty was acknowledged "de jure" in 1830. In 1821, the Greeks declared war on the Sultan. A rebellion that originated in Moldavia as a diversion was followed by the main revolution in the Peloponnese, which, along with the northern part of the Gulf of Corinth, became the first parts of the Ottoman empire to achieve independence (in 1829). By the mid-19th century, the Ottoman Empire was called the "sick man" by Europeans. The suzerain states – the Principality of Serbia, Wallachia, Moldavia and Montenegro – moved towards "de jure" independence during the 1860s and 1870s.