Siege Tower - Medieval and Later Use

Medieval and Later Use

With collapse of the Roman Empire in the West into independent states, and the Eastern Roman Empire on the defensive, the use of siege towers reached its height during the medieval period. Siege towers were used when the Avars laid siege unsuccessfully to Constantinople in 626, as the Chronicon Paschale recounts:

And in the section from the Polyandrion Gate as far as the Gate of St Romanus he prepared to station twelve lofty siege towers, which were advanced almost as far as the outworks, and he covered them with hides. —

At this siege the attackers also made use of "sows" - mobile armoured shelters which were used throughout the medieval period, and allowed workers to fill in moats with protection from the defenders (thus levelling the ground for the siege towers to be moved to the walls). However, the construction of a sloping talus at the base of a castle wall (as was common in Crusader fortification) could have reduced the effectiveness of this tactic to an extent.

Siege towers also became more elaborate during the medieval period; at the Siege of Kenilworth Castle in 1266, for example, 200 archers and 11 catapults operated from a single tower. Even then, the siege lasted almost a year, making it the longest siege in English history. They were not invulnerable either, as during the Fall of Constantinople in 1453, Ottoman siege towers were sprayed by the defenders with Greek fire.

Siege towers became vulnerable and obsolete with the development of large cannon. They had only ever existed to get assaulting troops over high walls and large cannon also made high walls obsolete as fortification took a new direction. However, later constructions known as battery-towers took on a similar role in the gunpowder age; like siege-towers, these were built out of wood on site for mounting siege artillery. One of these was built by the Russian military engineer Ivan Vyrodkov during the siege of Kazan in 1552 (as part of the Russo-Kazan Wars), and could hold ten large-calibre cannon and 50 lighter cannons. Likely, it was a development of the gulyay-gorod idea (that is a mobile fortification assembled on wagons or sleds from prefabricated wall-sized shields with holes for cannons). Later battery towers were often used by the Ukrainian Cossacks.