Ottoman Empire

The Sublime Ottoman State (Ottoman Turkish: Osmanlı İmparatorluğu), also known as the Ottoman Empire, was a Sunni Muslim and Turkic dominion that ruled the Eastern Mediterranean for an excess of six hundred years.

In 1299, the Byzantines had lost most of the Anatolian provinces, and as a result, Turkish Anatolia was divided into numerous Ghazi emirates. One of these Ghazi emirates was led by Osman I, which the empire would be later be entitled by.

Heading west
After Osman's death, the Ottomans rapidly conquered large territories in Anatolia and Greece previously owned by the Byzantine Empire. Their victory at the Battle of Kosovo ended Serbian power in the region and paved the entrance to Europe. In time, the Ottomans had conquered all the lands around the Byzantine Capital, Constantinople, though trouble struck when Timur of the Timurid Empire attacked Anatolia in the Battle of Ankara in 1402. He captured the Sultan and part of the Ottoman territories were lost. However, after a period of temporary disorder, Mehmed I became the Sultan and restored Ottoman power.

Conquest of Constantinople
The grandson of Mehmed was known as Mehmed II al Fatih (the Conqueror). He reorganized the military and state of the Ottoman Sultanate and prepared the final effort to conquer the Byzantine capital, Constantinople. In order to overcome the attack, the Byzantine Empire made an attempt of allegiance with the Pope and the Catholic Kingdoms by negotiating its conversion to Catholicism. Finally, the conversion was not accepted, and Constantinople fell under the Ottoman power in 1453, converting the city in the capital of the Ottoman Empire.

Aftermath
Ottoman people used various names for Constantinople including İstanbul, Qistantinya and later on İslambol (Turkish: lots of İslam). But Qistantiniya (without the first n, Arabic: city of Konstantin) was the name accepted and used by the state at the early years of the city's conquest. It officially took its final name, İstanbul, under the Republic of Turkey reign in 1930.