Rise of the Ottoman Empire
The foundation and rise of the Ottoman Empire is a period of history that started with the emergence of the Ottoman principality in , and ended with the conquest of Constantinople on May 29, 1453. This period witnessed the foundation of a political entity ruled by the Ottoman Dynasty in the northwestern Anatolian region of Bithynia, and its transformation from a small principality on the Byzantine frontier into an empire spanning the Balkans and Anatolia. For this reason, this period in the empire's history has been described as the Proto-Imperial Era. Throughout most of this period, the Ottomans were merely one of many competing states in the region, and relied upon the support of local warlords and vassals to maintain control over their realm. By the middle of the fifteenth century the Ottoman sultans were able to accumulate enough personal power and authority to establish a centralized imperial state, a process which was brought to fruition by Sultan Mehmed II (r. 1451-1481). The conquest of Constantinople in 1453 is seen as the symbolic moment when the emerging Ottoman state shifted from a mere principality into an empire, marking a major turning point in its history.
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.