The appearance of the Ottomans at the end of the 13th century created new dynamics in the Byzantine state and required the development of a broader defensive strategy.

In a short time, the initial raiders established permanent settlements in the region, and after increasing their army further due to their successes, they also engaged in the systematic conquest of important Byzantine cities.

When the Ottoman expansion also took place in the Balkan Peninsula during the second half of the 14th century, Constantinople appeared isolated from the rest of the world, surrounded by the Ottoman grip. The efforts to conquer it were now a matter of time.

The study compares the main offensive initiatives of the Ottomans against the Byzantine capital, in order to highlight the key factors that led to the fall of Constantinople in May 1453.

Specifically, it presents the Ottoman advance in the region of Asia Minor and the tactics they employed on the battlefield, whether against Byzantine military units or fortified city walls. The numerical data of the involved parties, available military resources, and the combat strategies followed by besiegers and besieged are documented and analyzed.

The consequences of the war are demonstrated, showing how as a social phenomenon it had immediate effects not only on the defenders but also on the civilian population of Constantinople, due to food shortages, population decline, and the fear of conquest by the foreign enemy.