During the thirteenth century, a group of Turkic people emerged from a region in the north-west Anatolian Peninsula, known as the Ottomans.
The leader of the Ottomans was a man by the name of Osman (known as Osman I, Osman Bey or Osman Gazi). He created a sizeable empire by taking territory from the Seljuk Empire in the fourteenth century, which was in decline and this was to mark the beginning of the Ottoman Empire.
The rulers of the Ottomans followed their leader Osman, declaring themselves as sultans. Over time, the ambitions of the Ottoman Empire became more military in nature as they began to master the use of gunpowder with cannons and muskets.
At this point, the Byzantine Empire was on its way out, which left the Ottomans free to dominate the territories left behind. Notably, the Bosporus and Dardanelles.
The Battle of Kosovo in 1389 really solidified and helped to expand the Ottoman Empire with the defeat of the Serbs and by early on in 1400 the Ottomans had also conquered the entire region of Bulgaria as well.
At this point, the Ottoman Empire was big enough and powerful enough to attempt the siege and conquest of the city of Constantinople (the former name for Istanbul).
During the 16th and 17th centuries, the Ottoman Empire was one of the most powerful states in the world, under the reign of Suleiman the Magnificent. They were multinational and multilingual, and they controlled large parts of Southeast Europe, Western Asia, North Africa, Horn of Africa and the Caucasus.
In total, the empire contained 32 provinces and many vassal states, although some of these were later absorbed into the empire while others were granted various types of autonomy during the course of centuries.
From the conquest of Constantinople by Mehmed II in 1453, the Ottoman Empire was at the centre of the Eastern and Western worlds for over six centuries, finally being dissolved in the aftermath of World War 1. This lead to the new state of Turkey emerging in the Ottoman Anatolian heartland, as well as the creation of modern Balkan and Middle Eastern states.