The fall of Constantinople in 1453 was caused by numerous factors, predominantly the strategic military actions of the Ottoman Empire led by Sultan Mehmed II. The city, which had been a bastion of Christianity and the Byzantine Empire, was heavily fortified but faced significant challenges, including dwindling resources and a declining population. The Ottomans employed advanced artillery, notably large cannons, and used strategic tactics, such as cutting off supplies and employing siege warfare techniques, to breach the city walls. The fall marked the end of the Byzantine Empire, transforming the city into a pivotal center of the Muslim world and significantly impacting European trade routes and political dynamics.