- from Byzantine Empire
By April of 1453 CE, Constantine XI knew that trouble was coming. He was the Byzantine emperor at that time. The new sultan of the Ottoman Turks, 21-year-old Mehmed II, was planning to attack Constantinople.
Mehmed II had built a fortress at the opening of the Bosporus Strait. This cut off Constantinople from its allies, or partners, on the Black Sea. Constantine XI asked western Europe for help. He even tried sending gifts to the sultan. But Mehmed II killed the Byzantine ambassadors who brought them. The Ottoman Turkish army was much bigger than Constantinople’s. But the emperor hoped the defenders could hold out until help came from Europe.