The word “Kilitbahir” means “Key to the Sea.” It reflects the critical role of the fortress built here to defend the Dardanelles Strait and the entire Ottoman Empire. During the siege of Constantinople by the Ottomans in 1453, the Genoese fleet managed to get through the Dardanelles in an unsuccessful attempt to save the capital of the Byzantine Empire. Mehmed the Conqueror drew the right conclusions from this situation and later decided to strengthen the Dardanelles with a chain of strategically placed fortifications. The immediate reason for the construction of fortresses on both shores of the Dardanelles were the fears of the sultan that the Venetians would attempt to wrestle Constantinople from the Ottoman control. The Italians spoke of these fortresses simply as i Castelli that is the castles.