Constantinople was the capital of the Eastern Roman Empire, located at the eastern tip of the Balkan Peninsula, guarding the gateway to the Black Sea.
In the thousand years since its founding, Constantinople has suffered 22 sieges, and only the Venetians and Ottomans have breached the city.
In 715 AD, the Arab Empire led an army of 100,000 to attack Constantinople, besieging it for five years, but there was no way to break through the walls of Constantinople, and finally had to withdraw.
The walls of Constantinople had a fourfold defense system. The unique defense system made it an almost impossible fortress to break in the Middle Ages.
The first heavy, the moat and the low wall. The moat here has dried up, but the low walls are still there. The attacker must first climb over the low wall, and the horses and siege vehicles will be blocked by the low wall.
The second is the façade. The outer walls of junbao were 7 to 8 meters high, made of limestone strips of stone, and were one of the strongest building materials at that time.
The third, the inner wall. The interior wall is 12 to 14 meters high, also made of granite strip stone, and is one of the tallest walls in the ancient Mediterranean world. The inner wall is not connected to the outer wall, and during the siege, even if the siege weapon is used to collapse the outer wall, there is an inner wall of more than ten meters high to protect the city.
Fourth, the tower. The tower is 18 to 20 meters high, there is one every 40 to 50 meters behind the city wall, and there are more than 500 towers in the Junbao Castle. Archers and crossbowmen can stand on towers and shoot, with the density of the towers of the Fortress, and any section of the city wall is within the effective range of the towers.
When the attacking soldiers approach the Fortress, they will be shot by crossbowmen in the outer city, the inner city, the tower, and the three directions.
After climbing the outer wall, the attacking soldiers had to fight the defenders on the city wall, and on the other hand, they had to suffer long-range attacks such as stones, crossbows, and guns on the inner wall and towers, and it was difficult to stand on the city wall.
Even if the attackers occupied the outer wall, they could not enter the city. In front of them, there was also an inner wall more than ten meters high.
It was not until 1453 that the Ottomans relied on cannons to destroy the walls of Constantinople, breaching the city in one fell swoop and destroying the Roman Empire that lasted for a thousand years.