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.
Dissolution of the Ottoman Empire
Europe became dominated by nation states with the rise of nationalism in Europe. The Ottoman Empire was a religious empire. The 19th century saw the rise of nationalism under the Ottoman Empire which resulted in the establishment of an independent Greece in 1821, Serbia in 1835, and Bulgaria in 1877-8. Many of the local Muslims in these countries died during the conflicts and massacres while others fled. Unlike the European nations, the Ottoman Empire made no attempt to integrate conquered peoples through cultural assimilation. The Porte had no official policy of converting the non-Muslims of the Balkans or Anatolia into Islam. Instead, Ottoman policy was to rule through the millet system, constituting of confessional communities for each religion..