The Medieval Siege

The siege was the most common type of battle fought during the Middle Ages.   Medieval armies and commanders tended to avoid pitched battles unless forced into them by circumstances.   Medieval warfare and its concentration on sieges can thus be considered the ultimate in positional warfare as success usually lay with control of castles and strong points and the terrain they dominated.

In the early medieval period, there was not much in the way of new construction of fortifications and therefore not many examples of siege warfare.   As the peoples of Europe began to organize themselves and nations and strongmen emerged there was a renewed focus on defensive fortifications that led to the castellation of Europe beginning in the tenth century, which was substantially completed by the end of the twelfth century.  

It is generally accepted that the first purpose built castle in Europe was built in the Loire valley of France around 950.   The castle at Langenais was built as part of the long struggle for supremacy between the counts of Blois and Anjou.   The borders of the two counties were fortified and castles were built offensively to deny territory to the other.   Count Fulk of Anjou demonstrated this with the series of castles he constructed to surround and capture the city of tours in the eleventh century.   The offensive use of castles led to many sieges as those threatened by these castles laid siege to them to eliminate the threat they posed.

During most of the medieval period, siege techniques were relatively unchanged as the pace of technological growth was slow.   The main difference in sieges was the mix of methods attempted and not the novel technologies used.

Sieges can be separated into two types based on their duration, either short or long.   It is axiomatic that if a castle or town did not fall quickly then the besiegers had to be prepared to try to starve the defenders into submission.   The most preferred method of quickly ending or even avoiding a siege altogether was to attempt to storm the castle.   If storming were unsuccessful then various other strategies could quickly end the siege such as negotiation and treachery.   If these quick methods failed then a blockade had to be mounted which could prove more damaging to the besieger than the besieged.

Blockade of a castle or town was not the preferred method of taking a fortified place for several reasons.   Camps quickly became unsanitary and rife with disease, blockades were manpower intensive, and armies were expensive to maintain, even the relatively modest sized armies of the Middle Ages.   There was also the risk that a relieving army would arrive and cause the attacker to lift the siege.

Cannon did not become widely used until the late fourteenth century and before that time, the weapons were basically the same as those used in antiquity.   The most common were stone throwers, which were used to batter down the walls of castles and towns.   The Middle Ages saw the invention of the trebuchet, which was a counterweight stone thrower that could lob huge stones at the walls of castles and towns.   Other engines used were battering rams and towers.   Rams were covered with frames that were protected with wooden armor and skins against fire, they were pushed against walls where they would repeatedly strike the walls or gates in attempt to weaken them and cause a breach.   Great towers on wheels were constructed that could overtop walls to allow attackers access.

What all of the engines used before the invention of cannon had in common is that they were not extremely powerful relying on torsion power to propel missiles.   This led to the construction if tall and relatively thin walls for protection.   Siege warfare often became blockade because of the lack of a good method for battering down walls.   It would wait for the development of cannon for an efficient method of breaching town walls.

The siege warfare of the early medieval period is notable only for its similarity to the siege warfare of antiquity.   Medieval man stood on the shoulders of the ancients in the technology and methods he chose to use.   This would all begin to change starting in the fourteenth century as cannons and gunpowder weapons appeared.