Mehmed II's Cannon Breach the Theodosian Walls and Constantinople Falls
After 53 days and a Hungarian gunsmith's giant cannon, the Roman Empire ends where it began
Quick facts
- Ottoman sultan
- Mehmed II
- Last Byzantine emperor
- Constantine XI Palaiologos
- Siege
- April 6 to May 29, 1453 CE
- Key weapon
- Urban's cannon, the Basilic
What happened
By 1451 CE, when Sultan Mehmed II took the Ottoman throne, Byzantium had shrunk to little beyond Constantinople itself, still protected by the Theodosian Walls that had held for over a thousand years. Mehmed besieged the city for 53 days beginning April 6, 1453 CE, deploying cannon built by the Hungarian gunsmith Urban, who had originally offered his services to the Byzantines before Constantine XI could not meet his price. The largest gun, called the Basilic, stretched 7.3 meters and weighed more than 18,000 kilograms, requiring 90 oxen and 400 men to move and capable of firing a 550-kilogram ball over a mile. Constantinople's ancient walls, built to withstand siege engines and battering rams, could not withstand sustained gunpowder artillery, and the city fell on Tuesday, May 29, 1453 CE, with Constantine XI, the last Roman emperor, dying among his soldiers in the final assault.
Why it matters
The fall ended a Roman imperial line that traced back unbroken more than eleven centuries to Constantine's founding of the city, and gave the Ottomans a capital they would hold for nearly five centuries afterward. It stands as one of history's clearest demonstrations of gunpowder artillery overturning fortifications that had defined siege warfare for a thousand years.
How we know
The World History Encyclopedia's dedicated article on the 1453 fall documents the 53-day siege, Urban's cannon, and the city's capture on May 29, 1453 CE, drawing on Byzantine and Ottoman chronicle accounts of the final assault.
Sources
- World History Encyclopedia. 1453: The Fall of Constantinople · Reputable sourceworldhistory.org · The domain "worldhistory.org" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
- World History Encyclopedia. Mehmed II · Reputable sourceworldhistory.org · The domain "worldhistory.org" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
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Related timelines
- The Ottoman Empire → · Mehmed IIs Ottomans took the city and made it their capital