By the 15th century, the Byzantine Empire was a shadow of its former self, consisting of little more than the city of Constantinople and its surroundings.

The rising Ottoman Empire, under Sultan Mehmed II ('the Conqueror'), made the conquest of the city its primary strategic goal.

Mehmed II assembled a massive army and commissioned enormous cannons, including the 'Great Turkish Bombard,' to breach the city's formidable walls.

The final siege of Constantinople began in April 1453.

The city was defended by a small force of around 7,000 men, led by the last Byzantine Emperor, Constantine XI Palaiologos.

A key Ottoman tactic involved dragging their ships overland into the Golden Horn harbor, bypassing a defensive chain that blocked the entrance.

After a 53-day siege, the final Ottoman assault on May 29, 1453, breached the walls, and the emperor was killed in the fighting.

The city was subjected to a three-day sack by the victorious Ottoman army.

Mehmed II made Constantinople the new capital of the Ottoman Empire, which it remained until the 20th century.

The fall of Constantinople is a major historical turning point, often used by historians to mark the end of the Middle Ages.