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).
Transformation of the Ottoman Empire
The changing nature of sultanic authority led to several political upheavals during the seventeenth century, as rulers and political factions struggled for control over the imperial government. In 1622 Sultan Osman II was overthrown in a Janissary uprising. His subsequent regicide was sanctioned by the empire's chief judicial official, demonstrating a reduced importance of the sultan in Ottoman politics. Nevertheless, the primacy of the Ottoman dynasty as a whole was never brought into question. Of seventeenth-century sultans, Mehmed IV was the longest reigning, occupying the throne for 39 years from 1648 to 1687. The empire experienced a long period of stability under his reign, spearheaded by the reform-minded Köprülü family of grand viziers. This coincided with a period of renewed conquest in Europe, conquests which culminated in the disastrous Siege of Vienna in 1683 and the fall from grace of the Köprülü family. Following the battle a coalition of Christian powers was assembled to combat the Ottomans, bringing about the fall of Ottoman Hungary and its annexation by the Habsburgs during the War of the Holy League (1683–99). The war provoked another political crisis and prompted the Ottomans to carry out additional administrative reforms. These reforms ended the problem of financial insolvency and made the transformation from a patrimonial to a bureaucratic state a permanent one.