Battles & Wars › Medieval wars › Gunpowder and cannon
Bombards: giant siege guns
c. 1380s–1450s; Orban's great gun, 1453· Invention or discovery· Weapons, armor & warships
Well documentedSolid records, physical evidence or scientific consensus.
The first giant siege cannon, firing huge stone balls, which made the tall walls of medieval castles and cities obsolete.
See it on the Battles & Wars map →What happened
Bombards were the first great siege guns. Early ones were built like barrels, from wrought-iron bars hooped together; later ones were cast in bronze. They fired stone balls weighing up to several hundred kilograms, but slowly: the biggest managed only a few shots a day and needed earthworks to shield crews. Survivors include Mons Meg (1449) in Edinburgh Castle and the Ottoman Dardanelles Gun (1464), about 17 tonnes, now in England.
Why it matters
They made high medieval walls obsolete. French royal guns retook English-held Normandy in 1449–1450 and Gascony in 1451–1453, helping end the Hundred Years' War, and Ottoman guns breached Constantinople in 1453.
How we know
Surviving guns such as Mons Meg, Dulle Griet in Ghent and the Dardanelles Gun at Fort Nelson; royal accounts of gun-making costs; and siege chronicles such as those of Constantinople by Kritovoulos and Doukas.
Still debated
How decisive bombards were is debated, since many sieges were still won by starvation or treachery. Chroniclers often exaggerated their sizes and ranges.
Connections (4)
▸Bombards: giant siege guns battered the walls at the Fall of ConstantinopleWell documented
The connection
From April 6, 1453, Ottoman bombards fired stone balls at Constantinople's thousand-year-old Theodosian land walls. Walls built tall and thin for older siege methods cracked, and defenders patched them nightly with timber and earth. After seven weeks of bombardment, Ottoman troops broke in on May 29.
When and how
Land walls of Constantinople, April 6 – May 29, 1453; perhaps about 70 Ottoman guns in batteries.
How we know
Eyewitness accounts by Nicolò Barbaro and Leonard of Chios, and Byzantine historians, describe the gunfire and the damage.
Debates and open questions
How much the guns decided the outcome, versus Ottoman numbers and the defenders' exhaustion, is debated; one account says the break-in came through a small gate left open.
▸Mehmed II the Conqueror commissioned Orban's great Bombards: giant siege gunsWell documented
The connection
Mehmed II prepared the siege like a major construction project. He hired Orban at a high wage, paid for the bronze, and asked for a gun big enough to breach Constantinople's walls. He reportedly took personal interest in the casting and the test firing at Edirne in early 1453.
When and how
Edirne (Adrianople), the Ottoman capital, winter 1452–53; test-fired before being hauled toward Constantinople.
How we know
Doukas and Kritovoulos, writing within a few decades, describe Mehmed's orders and the test firing.
Debates and open questions
Kritovoulos flattered Mehmed, so the sultan's personal role may be exaggerated, and the gun's specifications vary by source.
▸Bombards: giant siege guns spurred the low star forts of The military revolution (pike, shot and star forts)Mostly agreed
The connection
Cannon smashed high, thin medieval walls. In response, Italian engineers from about 1500 designed low, thick forts with earth-backed walls and angled bastions: the trace italienne, or star fort. These were costly to build and needed huge armies to besiege, a key point in the military revolution argument.
When and how
Italy, after the French invasion of 1494, then across Europe; star forts spread to the Netherlands, Malta and European colonies.
How sure are we?
Surviving star forts, engineers' treatises, and records of fortification and siege costs show the shift.
Debates and open questions
Historians debate whether star forts drove army growth, as Geoffrey Parker argues, or whether state finance and politics mattered more.
▸Orban and the Ottoman cannon foundries cast some of the largest Bombards: giant siege gunsWell documented
The connection
Orban cast his great bombard in bronze, a harder feat than hooping iron bars together. It was about 8 meters long and fired stones of perhaps 270–550 kilograms, making it among the largest guns yet built. Ottoman founders went on to cast similar giants.
When and how
Edirne, winter 1452–53; Orban and Ottoman founders.
How we know
Byzantine and Venetian accounts give its size, and the similar 1464 Dardanelles Gun, cast in two screw-together sections, survives.
Debates and open questions
Accounts differ on its size and on whether it cracked during the siege; estimates of its ball weight vary by a factor of two.