Siege Weapons

Category Overview

Overview

Siege weapons are specialized weapons systems designed to attack or reduce fortifications — to breach walls, destroy gates, kill defenders on walls, or project incendiary and biological agents over defensive perimeters. The history of siege weapons is the history of the contest between attack and defense in fixed positions, driving both weapons innovation and architectural innovation in parallel.

Categories of Siege Weapons

Direct Assault

• Battering ram — Heavy beam (often suspended) swung against gates and walls; iron-shod tip; protected by a penthouse; among the oldest siege weapons
• Siege tower — Mobile tower on wheels rolled against walls; allowed attackers to fight on the same level as defenders

Indirect Fire (Pre-Gunpowder)

• Catapult (tension/torsion) — Uses wound rope, sinew, or hair under torsion; throws projectiles in a low trajectory
• Ballista — Giant crossbow; fires bolts or stones accurately at long range; torsion-powered
• Onager — Single-arm sling catapult; throws heavy stones in a high arc
• Trebuchet — Counterweight engine; the most powerful pre-gunpowder siege weapon; could throw 150+ kg stones 200+ meters with accuracy; the dominant siege weapon of the 12th–14th centuries

Gunpowder Artillery

• Bombard — Early cannon; heavy stone or iron ball; the fall of Constantinople (1453) demonstrated the bombard's power against medieval walls
• Mortar — Short-barreled, high-angle; fires shells in a plunging arc over walls
• Siege gun — Heavy cannon; reduced fortifications systematically; drove the trace italienne defensive revolution

Area Weapons

• Greek fire — Byzantine incendiary; projected by pump; burned on water; composition unknown; devastating against wooden ships and siege equipment
• Incendiary projectiles — Pitch-coated burning materials catapulted into besieged areas
• Disease (biological) — Corpses catapulted into besieged cities to spread plague; recorded at the Siege of Caffa (1346)

The Fortification Response

Every advance in siege weapons drove fortress design evolution:

• Thick earthwork walls absorbed cannon fire (replacing thin stone walls)
• Bastion forts eliminated dead ground where rams could approach
• Concentric castles doubled the defensive perimeter
• Modern hardened bunkers use reinforced concrete

This article is a stub. Contributions covering specific siege weapons, fortifications, and famous sieges are welcome.