By April of 1453 CE, the Byzantine Emperor Constantine XI knew that trouble was coming. The new sultan of the Ottoman Turks, 21-year-old Mehmed II, was planning an attack on Constantinople.
Mehmed II had built a fortress at the mouth of the Bosporus Strait. This isolated Constantinople from its allies, or partners, on the Black Sea. Constantine XI sent for help from western Europe. He tried to avoid war by sending ambassadors to the sultan with gifts. But Mehmed II had the Byzantine ambassadors killed. The emperor knew that the Ottoman Turkish army was much bigger than Constantinople’s. But he hoped the defenders could resist long enough for help to arrive from Europe.
