Battles & Wars › Medieval wars › Castles and siege warfare
Trebuchet (traction and counterweight)
traction type in China by the 300s BC; counterweight type from the 1100s· Invention or discovery· Weapons, armor & warships
Mostly agreedGood evidence; some details, dates or numbers uncertain.
A lever-arm siege engine that hurled stones, first pulled by teams of people, later powered by a heavy falling counterweight.
See it on the Battles & Wars map →What happened
The traction trebuchet appeared in China by the 300s BC: a crew hauled ropes on the short end of a pivoted beam, and a sling on the long end flung the stone. It reached the Mediterranean in the late 500s. In the 1100s a counterweight type appeared, replacing the crew with a box of earth or stones weighing several tons. Large ones threw stones of 50–100 kg (110–220 lb) or more some 150–300 m, wearing down walls over days.
Why it matters
It was the most powerful siege weapon before gunpowder. Counterweight machines made strong stone walls vulnerable, pushing builders toward thicker walls and rings of defenses.
How we know
Chinese texts such as the Mozi; an Arabic treatise by al-Tarsusi written for Saladin in the 1180s; drawings by Villard de Honnecourt; and modern working reconstructions.
Still debated
Where and when the counterweight version was invented, in Byzantium, the Islamic world or the crusader states, is debated.
Connections (4)
▸Siege of Zhongdu (Beijing) taught the Mongols Chinese siege engines like the Trebuchet (traction and counterweight)Mostly agreed
The connection
Steppe horsemen could not take walled cities on their own. In the Jin wars the Mongols recruited or captured Chinese and Khitan engineers who built traction trebuchets, siege towers and fire weapons. These engineers, later joined by Muslim specialists with counterweight trebuchets, became a permanent Mongol siege corps.
When and how
North China, 1211–1215 and after; later, Muslim engineers built counterweight trebuchets for Kublai Khan at Xiangyang, 1273.
How sure are we?
Chinese and Persian sources record Mongol siege-engineer units and named engineers; Rashid al-Din and the Yuan History describe their use.
Debates and open questions
How much the Mongols learned at Zhongdu itself, versus earlier against the Western Xia, is unclear; Zhongdu fell mainly to blockade and hunger.
▸Catapult and ballista (torsion artillery) was succeeded in sieges by the Trebuchet (traction and counterweight)Mostly agreed
The connection
Torsion engines needed skilled builders and large amounts of sinew or hair rope, and the know-how faded after Rome's collapse in the West. The traction trebuchet, simpler to build and worked by a crew pulling ropes, arrived from the east in the late 500s and became the main stone-thrower of the Mediterranean world.
When and how
The Balkans and eastern Mediterranean, late 500s; an Avar siege of Thessalonica is among the first recorded uses.
How sure are we?
The Miracles of Saint Demetrius describe the Avar engines, and references to torsion machines become rare after the 400s.
Debates and open questions
How long torsion artillery survived, especially in Byzantium, and whether traction trebuchets came west via the Avars, Persians or others, is debated.
▸Trebuchet (traction and counterweight) battered city walls during The CrusadesWell documented
The connection
Crusader and Muslim armies both relied on trebuchets in the many sieges of the Crusades, from Nicaea and Antioch to Acre. Muslim engineers, such as those writing for Saladin, described powerful counterweight machines. At Acre in 1291 the Mamluks reportedly brought dozens of engines, helping take the last major crusader stronghold.
When and how
The Levant, Anatolia and Egypt, 1097–1291; crusader, Byzantine, Ayyubid and Mamluk engineers.
How we know
Chroniclers on both sides describe trebuchets in sieges, and al-Tarsusi's treatise written for Saladin details their design.
Debates and open questions
Whether the counterweight trebuchet was invented by Byzantines, Muslims or crusaders during these wars is still argued.
▸Trebuchet (traction and counterweight) was finally replaced by Gunpowder and cannonWell documented
The connection
By the late 1300s cannon could bring down walls faster than trebuchets, and their power grew quickly. Trebuchets lingered alongside guns for decades, but by the late 1400s cannon dominated sieges. Hernán Cortés's improvised trebuchet at Tenochtitlan in 1521 failed, one of its last recorded uses.
When and how
Europe and the Middle East, about 1350–1500; the Ottoman cannon at Constantinople in 1453 showed the change.
How we know
Siege accounts list both kinds of engine together before trebuchets disappear; Bernal Díaz describes the failed one at Tenochtitlan.
Debates and open questions
Early cannon were not clearly better than big trebuchets; when guns truly overtook them, and where, varied and is debated.