He was born in Edirne, the then capital city of the Ottoman Empire state. His father was sultan Murad II (1404-51). At the age of 21, he conquered Constantinople, bringing an end to the medieval Byzantine Empire. He also claimed the title of Caesar of Rome in addition to his other titles, Ottoman Sultan and Caliph, after the conquest of Constantinople. Mehmed II’s reign is also well-known for the religious tolerance with which he treated his subjects, especially among the conquered Christians, which was very unusual for Europe in the middle ages.