Throwing Power: From the Sling to the Siege Mortar

The sling is the simplest stop on the path: a pouch on two cords that hurls a stone or lead bullet. Its recorded history reaches back to about 2500 BC, when the oldest surviving slings, radiocarbon dated, were recovered from coastal sites in Peru. Armies later fielded dedicated slinger units, so the cheapest missile weapon stayed in use for millennia.

The war chariot carried the archer to the target instead of the missile alone. The oldest known chariots come from Sintashta burials in what is now Russia, dated to about 1950 to 1880 BC, and the light spoked wheel made them fast. The Battle of Kadesh around 1274 BC between Hittite and Egyptian forces is named as one of the largest chariot engagements of the Late Bronze Age.

The mangonel scaled the sling up to a machine. A crew pulled ropes on one end of a pivoting beam, and a sling on the other end launched the load. It began in China in the Warring States period and had spread across Eurasia by the sixth century AD. The Jin dynasty is recorded deploying 5,000 of them at the siege of Kaifeng in 1126, until the counterweight trebuchet replaced it.

The gastraphetes, or belly bow, was a hand-held crossbow of the ancient Greeks. The shooter braced the stock against the stomach and used body weight to draw the string, storing more energy than an ordinary bow allowed. The description ties it to the engineering tradition of Syracuse and to the larger torsion artillery that followed.

The chu-ko-nu answered the slow reload of the crossbow. It is a repeating crossbow invented in Warring States China that combined spanning the bow, placing the bolt and shooting into one motion, with a magazine of bolts above the stock. The earliest archaeological evidence comes from a Chu tomb at Qinjiazui in Hubei. It gave up range and power for a high rate of fire.

The Roman scorpio is a small torsion bolt thrower, a portable relative of the ballista. Polybius reports smaller, more portable ballistae called scorpions in use during the Second Punic War. Where the mangonel lobbed stones over walls, the scorpio was a direct-fire weapon aimed at individual targets, which is why ancient writers link it to point defense and picking off exposed men.

The arbalest brought the crossbow into the steel age. It came into use in Europe around the 12th century and replaced wood or composite prods with steel, needing a mechanical spanning device such as a windlass or cranequin to draw it. The power came at the price of a slow reload. The Second Lateran Council of 1139 tried to ban crossbows as too lethal among Christians, and the ban was widely ignored.

The siege mortar ends the path where gunpowder takes over the missile. It fires explosive shells in a high arc so they drop inside fortifications, which a flat-firing cannon could not do. Its first recorded use in siege warfare was the 1453 siege of Constantinople by Mehmed the Conqueror, and later engineers such as Vauban combined mortar fire with trenches and breaching batteries.