Once upon a time in Anatolia, in the late 13th century a Turkic principality – one of many shaped in the wake of the Mongol invasion of the 1240s – consigned the Seljuk Turks to the past and emerged as the Ottoman emirate. It was named after its founder, Osman I. By the middle of the 15th century, the time of the game-changing conquest of Constantinople by Sultan Mehmet II, the expanding Ottoman empire had absorbed virtually all its neighboring Turkic emirates. And by the start of the 16th century, what sprang up was a multi-religious and multi-ethnic empire that – pragmatic and tolerant – ruled for four centuries over the Balkans, Anatolia and Southwest Asia.