Orban: The Man Who Brought Down the Walls of Constantinople – Part 2


For 53 days, the forces of the Ottoman Empire shook what was left of the Eastern Roman Empire (known as Byzantium, or the Byzantine Empire) until they were able to breach the massive walls of Constantinople, conquering the last standing remnants of the once mighty Roman Empire.

Sultan Mehmed II was so pleased with Orban’s massive, destructive cannon that he wanted another twice its size! Orban headed back to his foundry in Edirne (Adrianople) acquiring more timber and bronze, and in three months he produced a twenty-seven-foot-long monster that had a diameter of 2.5 to three feet (76.2 to 91.44 cm) and could fire a stone projectile weighing between 1440-1500 lbs (653 – 680 kg).

[Read Part 1]

Moreover, to make sure this weapon fire properly without exploding, the barrel was walled with eight inches (20 cm) of solid bronze to absorb the force of the blast. This massive weapon was finished in January 1453.

Citizens were warned in the surrounding area not to panic if they heard a loud boom:

“In January [the Sultan] decided to test the cannon which the Hungarian had made. It was carefully set in position before the main gateway leading into the palace [at Adrianople] which he had built that year, the ball was fitted into it, and its ration of powder weighed out. It was planned to fire it the next morning, and public announcements were made throughout Adrianople, to advising everyone of the loud and thunderous noise which it would make so that no one would be struck dumb by hearing the noise unexpectedly or any pregnant women miscarry. In the morning the gunpowder was lit, there was a great rush of hot air, and the shot was driven forth, leaving the cannon with a loud explosion which filled the air with clouds of smoke. The sound was heard a hundred stadia away, and the shot travelled a thousand paces from the point of firing, making a hole six feet deep at the point where it landed.”

Seeing potential in this new weapon, Mehmed ordered the production of more, but in smaller caliber. Once finished, the number of cannons produced was 14 large and 56 small; all of which would be used to batter the walls of Constantinople.

On the Move, Setting Up and Firing!

After the cannons had been tested and they were deemed ready for service, the Sultan Mehmed sent out the order to his officers to muster the forces and meet at the Ottoman capital of Edirne. The size of the Ottoman force that was to lay siege to Constantinople is uncertain. Some suggest the Ottoman army was 50,000–80,000 or 80,000-100,000 troops. Others say 120,000 and some go as high as 300,000 with 120,000 non-combatants in attendance.

Map of Constantinople (1422) by Florentine cartographer Cristoforo Buondelmonti is the oldest surviving map of the city, and the only one that predates the Turkish conquest of the city in 1453 (Public Domain)

Once the army arrived outside the walls of Constantinople, much of the smaller artillery likely accompanied the main force. As for the heavier cannon pieces, particularly the famous Basilica, or the Ottoman Cannon, it took 70 oxen and 10,000 men even though other sources suggest only 1,000 men. The move from Edirne to Constantinople was a distance of 140 miles (225 kilometers).

Bronze cast Ottoman bombard, Cast in the 15th–16th century,  Fired shots of 1,000 lbs. (453 kg) (CC BY-SA 3.0)

The Long Haul

Moving the large cannon, as one can image, was a laborious task. To move this gargantuan weapon of war, the tube had to be lifted and placed on a number of attached wagons, which as mentioned, were pulled by many oxen. Scouts went ahead to report back of the terrain that lied ahead, while the men with the cannon had to help guide, push, and pull the wagons and beasts over the rolling Thracian countryside. Those workers ahead were tasked with leveling out the road as best as they could and building wooden bridges over the rivers and gullies. The total distance this juggernaut made was two-and-a-half-miles a day, (about four kilometers).

By the time Orban’s Basilica cannon arrived the Ottoman troops were already in position, Sappers had already been making a clear path for fire by cutting down the orchards and vineyards, while others dug ditches the length of the walls of Theodosius and 250 yards (228 meters) from them. It is safe to say that many of the smaller cannons had been set in place since Mehmed grouped the cannons into 14 or 15 batteries pointed at the walls’ vulnerable points.

The restored walls of Constantinople (CC BY-SA 3.0)

Exploiting Weakness

According to the Venetian physician and eyewitness Nicolo Barbaro, “These cannon were planted in four places: first of all, three cannon were placed near the palace of the Most Serene Emperor, and three other cannons were placed near the Pigi gate, and two at the Cressu gate, and another four at the gate of San Romano, the weakest part of the whole city.” The larger cannons would receive support by smaller ones in each battery. As for Basilica, it was placed in front of Mehmed’s tent so that he could watch and praise his new toy. Basilica had to be lifted from the wagons and lowered into position using a block-and-tackle system onto a sloping wooden platform. To protect the cannon from enemy fire, the men built a wooden palisade with hinged doors that would be opened when it was time to fire. Greek politician, scholar, and historian Michael Critobulus (1410-1470) mentions this as well and states:

After this, having pointed the cannon toward whatever it was intended to hit, and having leveled it by certain technical means and calculations toward the target, they brought up great beams of wood and laid them underneath and fitted them carefully. On these they placed immense stones, weighting it down and making it secure above and below and behind and everywhere, lest by the force of the velocity and by the shock of the movement of its own emplacement, it should be displaced and shoot wide of its mark.

Furthermore, the Ottomans still relied on tradition siege machines such as the trebuchet to batter the walls.

Counterweight trebuchet by the German engineer Konrad Kyeser (c. 1405) (Public Domain)

Barbaro also mentions Basilica: “One of these four cannon which were at the gate of San Romano threw a ball weighing about twelve hundred pounds, more or less, and thirteen quarte in circumference, which will show the terrible damage it inflicted where it landed.”

Critobulus describes the firing of the cannon stating: “And the stone, borne with enormous force and velocity, hit the wall, which it immediately shook and knocked down, and was itself broken into many fragments and scattered, hurling the pieces everywhere and killing those who happened to be nearby.”

Giant Ammunition

If the size and weight of the cannon was not enough, the ammunition was also another weightier matter. To bring forth such ammunition, it had to be hewed from the rock and shaped. The stone balls used were made on the north coast of the Black Sea. Besides the stone balls was the large need for saltpeter (potassium nitrate). Not only did the crews man, load, fire, and reposition after each shot, they also repaired what they could. This went for all the cannon batteries.

Critobulus mentions that when the cannon was fired the result from the impact was that “Sometimes it demolished a whole section, and sometimes a half-section, and sometimes a larger or smaller section of a tower or turret or battlement. And there was no part of the wall strong enough or resistant enough or thick enough to be able to withstand it, or to wholly resist such force and such a blow of the stone cannonball.”

Shots fired from Basilica sometimes did not hit their target but instead flew over the wall and traveled up to a mile into the city. As the ball came down it would mow through humans and property before settling into the ground causing a quake felt for two miles.

Assaulting under Fire and the Final Explosion

The 70 cannons of various sizes hurled stone projectiles continuously at the walls for 53 days. One can only imagine the psychological impact the cannons had on the citizens and defenders alike: the sound of loud sounds of stone balls flying right over your head and smashing into buildings, with the added knowledge that death was a matter of chance, and nearly a certainty.

Sultan Mehmed II – Mehmed the Conqueror (Public Domain)

Sultan Mehmed launched assault after assault during which his cannons were able to punch holes through walls or did enough damage that debris that fell down and created a ramp from which his armies could reach the breach in the wall. However, defenders on the walls were able to push and keep the invaders back.

The Fall of Constantinople, illustration from ‘Hutchinson’s History of the Nations’, 1915 (Public Domain)

While the Byzantine army did not have the sufficient manpower to defeat the Ottoman army in a head-on battle, the walls of Constantinople provided much safety and support. Understand that the Ottoman cannons took time to fire, which in turn allowed the defenders on the walls to repair the breaches made. In futility, Mehmed continued launching assaults that failed each time.

Mehmed’s strategy, as Roger Crowley states “was attritional—and impatient,” or what I like to call, attrition through impatience. Mehmed knew that as long as his cannons shot holes through the walls and he launched assault after assault, the citizens and defenders would soon to give up. According to the Greek scholar Melissenos, who was not there but collected articles that described the action a century later, mentions that the “assault continued night and day with no relief from the clashes and explosions, crashing of stones and cannon-balls on the walls, 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.” While wave after wave of Ottoman attacks continued along with the constant bombardment, Basilica began to break.

Holding a Tiger by the Tail

While Basilica was an awesome sight and sound to those firing the cannon and a terror to those receiving its wrath, truth be told, the weapon was more of a burden than a blessing. Loading and re-aiming the cannon took much time and it could only fire seven times a day. Another major issue with the cannon was that the production of such a weapon, on such a large scale, and under a deadline worried Orban—and rightfully so.

Using the colossal canon was like grabbing a tiger by the tail. It was in effect employing something powerful and dangerous that could hurt the wielder as much as any target.

An expert iron founder and engineer, Orban started to notice that hairline fractures began to appear on the cannon. After each shot, the crews had to quickly pour oil onto the barrel to prevent cold air from enlarging the fissures. Even when they tried to fit iron hoops around the barrel, it did little to support it. However, pouring warm oil was not enough and the cannon eventually “cracked as it was being fired and split into many pieces, killing and wounding many nearby.” Those killed in the blast supposedly included Orban. However, that is what Christian chroniclers wish happened.

Taking the City: The Fall of Constantinople and the Rise of Artillery

The entry of Sultan Mehmed II into Constantinople, painting by Fausto Zonaro (1854-1929) (Public Domain)

On 29 May 1453, the Ottoman forces of Mehmed finally made their way into the city. They defeated the remaining defenders, killing the last Roman Emperor Constantine XI in the streets which ended an Empire that lasted from 27 BC – 1453 CE.

Mosaic of Emperor Constantine I with a representation of the city of Constantinople (Public Domain)

While Mehmed made Constantinople the new capital of the Ottoman Empire, the cannon made by Orban also had an impact. The impact of Orban’s cannon had made little damage, but much noise. In other words, Orban’s attempt to produce a cannon of such magnitude showed the potential that could be harnessed if trial and error could be applied with sufficient time and testing. This would happen much later in Western Europe during the renaissance and beyond. The cannon produced by Orban was nothing more than a colossal weapon that produced lots of smoke, loud noise, and on occasion, landed on its target. Overall, the weakening and destruction of the walls of Constantinople were not due to just Basilica, but the combination of all the firepower at the Ottoman’s disposal—even the trebuchets.

The Tsar Cannon (caliber 890 mm), cast in 1586 in Moscow. It is the largest extant bombard in the world. (CC BY 3.0)

Basilica only made a name for itself due to its sheer size overshadowing the other cannons in their arsenal at the siege of Constantinople of 1453.

The final siege of Constantinople, contemporary 15th-century French miniature, 1455 (Public Domain)

Top Image: Detail; The entry of Sultan Mehmed II into Constantinople, painting by Fausto Zonaro (1854-1929) (Pubic Domain)

By Cam Rea


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