Siege Warfare (Siegecraft)

Roman siege warfare in particular combined systematic engineering, circumvallation and contravallation lines, siege towers and artillery with methodical logistics, the approach Caesar's own commentaries describe in Gaul.

Siege warfare blockades a fortified city or stronghold to force its surrender by attrition, starvation, disease or eventual assault, when a direct attack is impractical. Besiegers invest a target to cut its supply lines and escape routes, and may build a ring of fortified earthworks around it, circumvallation, sometimes paired with a second outward facing ring, contravallation, to hold off a relief force, the double wall method Julius Caesar used against Vercingetorix at Alesia in 52 BC. Bombardment by siege engines such as catapults and trebuchets, or later cannon, and mining under the walls, are used to breach fortifications directly, while storming parties use ladders, battering rams and siege towers once a breach is made or the defenders are weakened enough. The Romans were noted practitioners of systematic siegecraft; the Mongols instead destroyed an enemy's field armies first and starved the remaining cities into surrender, as at Samarkand in 1220. The fall of Constantinople in 1453, breached by cannon in six weeks, marked gunpowder artillery's arrival as a decisive siege weapon and the beginning of the end for medieval fortification design.