Mehmet II was Sultan of the Ottoman Empire for a short time from 1444 to September 1446, and later from February 1451 to 1481. At the age of 21, he conquered Constantinople, bringing an end to the Byzantine Empire. Mehmet continued his conquests in Asia, with the Anatolian reunification, and in Europe, as far as Belgrade. Administrative actions of note include the amalgamation the old Byzantine administration into the Ottoman state. It is notable that Mehmet II is not considered the first Turkic origin ruler of Constantinople. Before him, the Christian Leo IV the Khazar was a de jure Roman Emperor. Beside Turkish, he spoke French, Latin, Greek, Serbian, Persian, Arabic and Hebrew.