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.
Postage stamps and postal history of Turkey
The Ottoman Empire signed the secret Ottoman-German Alliance on August 2, 1914, and entered hostilities on the side of the Central Powers in October 1914. The war and its disruptions are reflected in Ottoman's stamps issued during the war, which included stamps depicting soldiers and battle scenes, a number of provisional stamp issues in which available stocks of older issues were overprinted due to paper shortages, and stamps issued to collect a tax for war orphans. Remainders of stamps as old as 1865 were overprinted, some of which already had overprints, and sometimes multiple new overprints were added, resulting in a complex variety of configurations of interest to philatelists. The Allied Forces were victorious and occupied Constantinople, after which the Ottoman government collapsed. The Treaty of Sèvres, August 10, 1920 confirmed the dismemberment of the Ottoman Empire.