Ottoman Empire

In 1299, The Byzantines had lost most of the Anatolian provinces. Turkish Anatolia was divided into Numerous Ghazi emirates. One of the Ghazi emirates was led by Osman who later had the empire named after him.

Heading west
After Osman's death, the Ottomans rapidly conquered the areas of the Byzantine Empire. Their victory at the Battle of Kosovo ended Serbian power in the region and paved the entrance to Europe. In some time the Ottomans had conquered all the lands around Constantinople. 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. After temporary disorder Mehmed the first, became sultan and restored Ottoman power.

Aftermath
Constantinople was renamed Istanbul after it's conquest. It remained the capital of the Ottoman empire until the decline of the Empire in 1923.