July 27: The day when Osman Bey founded the Ottoman Empire

As fans around the world desperately await the third season of Kuruluş Osman, the famous Turkish historical drama series, July 27 marks the 719th anniversary of the founding of the Ottoman Empire, which at its peak in the 15th and 16th centuries was spread across three continents.

On July 27th, 1302, Osman Bey defeated the Byzantine armies at the plain of Bapheus and marked the beginning of future Ottoman conquests. This has been defined by historians as the first major victory of Osman over the Byzantine imperial army.

Following his conquests of Bilecik, Yar-Hisar, İnegöl, and Yenişehir, and claiming his independence from the Seljuks in 1299, Osman Bey then proceeded to besiege the former Byzantine capital city of Nicaea (İznik). As a result, in the spring of 1302, the Byzantine Emperor Andronikos II Palaiologos sent his son and (co-emperor) Michael IX to relieve the city.

However, he was blockaded by Osman and his fellow warriors. Escape was the only option left for Michael IX. Again in July 1302, Andronikos II sent an army under George Mouzalon to fight against Osman. Eventually, both sides met at the plain of Bapheus near Nicomedia (Izmit).

Osman successfully won the battle forcing the Byzantines to withdraw into Nicomedia. After this defeat, the Byzantines effectively lost control of the countryside of Bithynia allowing the Ottomans to gradually annex it. After this victory, Osman bey was impossible to ignore.

The contemporary Byzantine chronicler Pachymeres describes how news of Osman’s victories spread and attracted Turks from other areas of western Anatolia to join his following, and how his force was strong enough to defeat a Byzantine army near Nicomedia (Izmit).

According to Halil İnalcık, at a time when Mehmed the Conqueror’s claim to universal empire had become a dynastic assertion to primacy among the states to the East and to the West, the Ottomans used Osman’s victory at Baphues as the dynasty’s legitimation to imperial sovereignty as early as the time of the dynasty’s founder.

This victory allowed the Ottomans to achieve the characteristics and qualities of a state. The Byzantine emperor, Andronikos II, refused to accept the loss of his territory to the Ottomans. And thus began the long Ottoman-Byzantine wars, in which the Byzantines gradually lost all of their territories in Anatolia to the Ottomans.

On July 24th, 1923, the treaty of Lausanne was signed by Turkey and the Allied powers that fought World War 1. Within the signing of the treaty, the 600-year-old Ottoman Empire came formally to an end.