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.
Secularism in Turkey
Sultan Selim III founded the first secular military schools by establishing the new military unit, Nizam-ı Cedid, as early as 1792. However the last century (19th century) of the Ottoman Empire had many far reaching reforms. These reforms peaked with the Tanzimat which was the initial reform era of the Ottoman Empire. After the Tanzimat, rules, such as those relating to the equalized status of non-Muslim citizens, the establishment of a parliament, the abandonment of medieval punishments for apostasy, as well as the codification of the constitution of the empire and the rights of Ottoman subjects were established. The First World War brought about the fall of the Ottoman Empire and the subsequent partitioning of the Ottoman Empire by the victorious Allies. Therefore, the Republic of Turkey was actually a nation-state built as a result of an empire lost.