Constantinople, the Ottoman Cannon, and Technology in Military History
During the Siege of Constantinople, the Ottomans rolled out one of the largest cannons in history. But did the cannon topple the Byzantine Empire?
Military technology changes how rival armies engage each other and which side wins battles. And leaps forward in technology can upend strategies and lead to unlikely outcomes.
Today, we picture tanks and aircraft carriers, machine guns, and atomic bombs when we think about military technology. But some of history’s leaps forward in military technology came from unlikely sources. And few compare with the introduction of gunpowder into combat.
Leaps in military technology changed the course of history — and sometimes, the impact of a technological advantage spread far beyond the battlefield.
In the 14th century, Chinese military engineers had begun to construct cannons. One Ming dynasty text described the technology as a “thousand ball thunder cannon.” At that time, gunpowder was an uncommon tool in European warfare. But the siege of Constantinople would prove that gunpowder was the future — and it would change warfare forever.
By the 15th century, centuries of siege warfare had proved that thick walls won sieges. The city of Constantinople had an outer wall and an inner wall. The inner wall was 15 feet thick and stretched 40 feet high. Nearly 100 towers lined the wall to defend the city. And those walls had never been breached in over a thousand years.
But gunpowder could tear down medieval walls — even the massive walls of Constantinople.
The Ottoman Cannon And The Siege Of Constantinople
In the 1450s, the Ottoman Turks had their eye on Constantinople. The ancient city could be the crown jewel of the Ottoman Empire — if the Ottomans could defeat the Byzantine Empire, which had stood for a thousand years.
The Ottomans — and others — had tried in the past. Muslim armies tried to take Constantinople in the 7th century. In over 20 attempts to besiege Constantinople, the city had never fallen. Its defenses were simply too strong.
The balance of power shifted, though, when the Ottomans cornered a new military technology: bronze cannons capable of blasting through the walls.
As summer turned to fall in 1452, Ottoman workers built the largest cannon the world had ever seen. They dug into the earth to create a casting pit and poured melted bronze into the mold. When the furnace cooled, an enormous cannon appeared.
Ottomans gazed upon the 27-foot cannon and called it “a horrifying and extraordinary monster.” They dubbed it Basilica, or the royal cannon.
The barrel of the Ottoman cannon was so large that a man could crawl inside. And each firing could propel a shot that weighed 1,500 pounds.
During its first test firing, the massive cannon let out a black cloud of smoke and deafened the crowd. The cannon blasted its projectile a mile and buried it six feet deep in the ground.
Armed with Basilica, the Ottomans believed they could finally take Constantinople. There was just one problem: they had built the cannon 140 miles away from the city. It would take 200 soldiers and 60 oxen to drag the cannon to Constantinople.
As the cannon made its slow journey, traveling under three miles a day, Ottoman workers continued to make more cannons. These were not as massive as Basilica, the 27-foot cannon. Instead, they were the smaller workhorses that would keep the Byzantines busy repairing cracks in their walls.
Six weeks later, the mighty cannon reached Constantinople.
Under Sultan Mehmed II, the Ottomans arranged their cannons to face the wall’s most vulnerable points. The Ottomans brought enough cannons to fill 15 batteries. Each battery contained a large cannon along with smaller ones, which the Ottomans described as “the bear with its cubs.”
As for the super cannon, it sat in front of Mehmed’s own tent.
Instead of the iron cannonballs that would dominate later warfare, the Ottomans used stones. The smallest weighed 200 pounds, while the largest topped 1,500 pounds.
Simply manning the cannons required enormous time and effort. Workers had to haul stones, erect palisade defenses, and use platforms to position the barrels. The stones came from the far-off Black Sea, where ships had to transport them to Constantinople. Saltpeter, sulfur, and charcoal were needed to create the gunpowder to fire the cannons.
Finally, the Ottomans were in place. While 8,000 Byzantines watched from inside the walls, an Ottoman force of 80,000 began its artillery barrage on April 12, 1453.
The Artillery Barrage
“There was first a terrifying roar and a violent shaking of the ground beneath and for a great distance around, and a din such as has never been heard,” wrote one eyewitness. “Then, with a monstrous thundering and an awful explosion and a flame that illuminated everything round about and scorched it, the wooden wad was forced out by the hot blast of dry air and propelled the stone ball powerfully out.”
But could the cannon fire blast through walls? The first barrage showed that the Ottoman strategy worked.
“Projected with incredible force and power, the stone struck the wall, which it immediately shook and demolished,” the eyewitness recorded. As for the stone, “it was itself shattered into many fragments, and the pieces were hurled everywhere, dealing death to those standing nearby.”
From inside the walls, the Byzantines waited for the smoke to clear. Would their city still stand?
“Sometimes it destroyed a complete portion of wall,” reported the eyewitness, “sometimes half a portion, sometimes a greater or smaller part of a tower, or a turret, or a parapet, and nowhere was the wall strong enough or sturdy enough or thick enough to withstand it, or to hold out totally against such a force or the velocity of the stone ball.”
And sometimes, the stone flew over the wall and into the city. When massive rocks struck churches, buildings, and homes, they simply crumbled.
Surrounded by smoke and noise, fearing death from the sky, Constantinople’s people wondered if the city falling to Ottoman control could possibly be worse than the attack.
But eventually, the Ottoman cannons fell silent. Still a finicky new technology, the cannons had to cool after firing before they could be reloaded. In fact, Basilica grew so hot during each firing that it took hours to fully cool so gunners could reload it.
During the moments of silence, Constantinople’s defenders tried to repair the cracks in their walls.
Suddenly, the walls designed by ancient Romans to withstand any attack — the walls that held through 20 sieges — seemed like nothing more than tapestries. Gunpowder and cannons had changed warfare forever.
The End Of The Ottoman Cannon
Sultan Mehmed was patient. He continued the artillery barrage and sent Ottoman raiding parties to attack holes in the wall.
“The assault continued night and day, with no relief from the clashes and explosions, crashing of stones and cannonballs on the walls,” a Byzantine defender complained, “for the sultan hoped in this way to take the city easily, since we were few against many, by pounding us to death and exhaustion, and so he allowed us no rest from attack.”
As the great cannon continued to assault the walls, the Ottomans worried that the bronze barrel might explode. The force of firing it several times a day had created fissures in the metal. Every time the cannon fired, crews rushed in to pour warm oil on the barrel to avoid more cracks.
Eventually, the cannon gave out.
Basilica “cracked as it was being fired and split into many pieces, killing and wounding many nearby.” But the Ottomans refused to give up their greatest advantage. So they wrapped iron rings around the barrel and began firing again. Yet the barrel cracked again, leaving the Ottomans without their greatest technological advantage.
The Ottomans learned a new form of artillery warfare as they went. Instead of aiming their assaults at the same part of the wall, they began creating triangular shot patterns designed to collapse the wall.
For six days, the Ottomans launched 120 stones at Constantinople. By the end of the week, part of the outer wall had crumbled. Towers on the inner wall had fallen as well. Byzantine defenders poured soil and stones into the holes, working at night to repair the craters. Soon, they learned that earth stopped the cannons better than stone walls.
But the attack continued.
On The Other Side Of The Wall
From inside the walls, the days began to run together. One Byzantine recorded, “On the 11th of May, nothing happened either by land or at sea except a considerable bombardment of the walls from the landward side . . . On the 13th of May . . . nothing significant happened during the whole day and night, except for continuous bombardment of the unfortunate walls.”
Ottoman cannons fired on the walls for nearly 50 days. The Ottomans burned through 55,000 pounds of gunpowder — a shocking amount in the 15th century. Over 5,000 stones had been hurled at the walls. Nine huge holes stood in the fortifications, filled in by earth.
Even without Basilica, the mighty cannon gave the Ottomans a psychological edge. From inside the walls, the Byzantines wondered if any city on Earth could withstand the cannon’s power. And days of relentless bombardment left nerves frayed in the Byzantine capital.
Finally, on May 29, 1453, with the cannons blasting, Ottoman troops assaulted the city. “The very air seemed to split apart,” one defender remembered. “It seemed like something from another world.”
A blast opened a gap in the wall, and when the smoke and dust cleared, Ottoman troops advanced into the breach. Hours later, Constantinople was in Ottoman hands. Soon, the mighty ancient city would take on a new name: Istanbul.
The Military Technology Edge
How did Mehmed and the Ottomans succeed where so many others had failed? Military technology gave the Ottomans the tool they needed to neutralize Constantinople’s strongest defense.
Constantinople’s fate might have been different. The Byzantines had an opportunity to corner the cannon market — and they passed up the opportunity.
Orban, the Hungarian inventor who created the 27-foot cannon, initially approached the Byzantine Empire. He was willing to build cannons to defend Constantinople. But the Byzantines turned down Orban’s offer for two reasons: the new technology cost too much and they didn’t have enough raw materials to craft enormous bronze cannons.
So Orban went to the Ottomans. During a meeting with Sultan Mehmet II, the Sultan asked Orban if his cannons could break through Constantinople’s fortifications.
“I can cast a cannon of bronze with the capacity of the stone you want,” Orban promised. “I have examined the walls of the city in great detail. I can shatter to dust not only these walls with the stones from my gun, but the very walls of Babylon itself.”
And the rest was history.
Did the Ottoman cannon win the war for the Ottomans? The massive cannon cracked before the city fell. And it was just one of dozens of cannons used during the siege. From that perspective, the cannon did not make the difference in the war.
Yet had the Byzantines manufactured their own cannon to turn away the army laying siege to their capital, the war’s balance might have shifted.
And even though the Ottoman cannon cracked, its legacy continued. In 1464, barely a decade after the Ottomans seized Constantinople, an Ottoman military engineer named Munir Ali rebuilt the super-sized bombard.
Ali’s model, known as the Dardanelles Gun, would sit at a strategic military location for decades. Also called the Great Turkish Bombard, the cannon’s final stand came in 1807, when the British navy attempted to sail into Turkish waters.
Even though the Dardanelles Gun had recently celebrated its 340th birthday, Turkish forces successfully loaded and fired the cannon at the British ships. In fact, the medieval weapon racked up 28 casualties during the 1807 bombardment.
Basilica’s brief moment in the spotlight did change military history. While the cannon itself lasted less than a year, its impact shaped centuries of warfare.
The story of the mighty Ottoman cannon reveals how a single moment in time — when the Byzantines turned down the cannon’s inventor — changed the course of history.
For more true stories from military history, check out War and Chance to discover the moments that changed the course of military history.
Bruce Wilson Jr. is the author of nine books on history. Visit Bruce Wilson’s website to learn more.
