Medieval sieges were conducted (sometimes) in accordance with rules based on five verses in the book of Deuteronomy, “But if it [the town] makes no peace with you, then you shall besiege it. And when the Lord your God gives it into your hand, you shall put all its males to the sword, but the women and the little ones, the livestock, and everything else in the city, all its spoil, you shall take as plunder for yourselves. And you shall enjoy the spoil of your enemies, which the Lord your God has given you. Thus you shall do to all the cities that are very far from you, which are not the cities of the nations here. But in the cities of these peoples that the Lord your God is giving you for an inheritance, you shall save alive nothing that breathes, but you shall devote them to complete destruction.”
A siege had to begin with a formal challenge. This would take the form of a missile of some kind being fired at the gates of the town or castle. At the beginning of the siege the besiegers had to demand the surrender of the town or castle and they had to offer terms for surrender. Sometimes the head of the garrison would ask leave to consult his lord, who was elsewhere. Sometimes this was permitted, sometimes not.
Once it had begun there were three ways a siege could end:
- Negotiated agreement
- Unconditional surrender, by either side
Sieges were expensive for those doing the besieging. They tied up a large number of soldiers whose interest in the siege waned the longer it went on. The supplies usually had to be brought long distances, often through hostile territory. Since the besieging army was in one place for months, there was always the chance that the enemy might send an army large enough to destroy them. Negotiating a surrender was usually the best option. Some garrisons were bought off by the besiegers so that they would surrender. Sometimes the parties agreed that a town would surrender if no relief army arrived before a certain time.
It was a balancing act for the besieged between holding out to the bitter end and suffering starvation and illness and being sacked if no relief arrived, and surrendering early and incurring the wrath of their lord. The leaders of garrisons that surrendered to the enemy could suffer terrible punishments from their lords, even if they were allowed to live.
Being a messenger or even a negotiator could be hazardous. It was not unknown for messengers bringing bad new to be killed by their own side, so taking messages to the enemy was even more precarious. Messengers and negotiators were often taken prisoner or killed as they went between the town and the besiegers.
Given what could happen if a siege continued to the bitter end, it’s not surprising that most ended with a negotiated agreement.
A storm was the taking of the town or castle by force. This could be by scaling the walls, breaking down the gates or walls by mining or siege engines, or by a small force finding a way in and opening the gates for the rest of the army. If the siege ended with a storm the attackers had complete control over the defeated. They could be enslaved, killed, raped and their homes and property seized. The defeated could expect no mercy.
The town could be sacked if it didn’t surrender and was successfully stormed. This happened at Limoges in 1370 where the town, which had surrendered to the French after three days, was held by the Black Prince to have committed treason. When the English and Gascon army arrived they successfully stormed the town after five days. The Black Prince would have been justified in killing all the inhabitants, but only about 300 were killed, about ten percent of the population. At Limoges there was no surrender and no negotiated agreement. What happened at Limoges was not exceptional.
Once the besiegers were inside after a storm, murder, rape and assault were the norm. Defending soldiers could often retreat to and hold the castle keep, so the civilians were usually the ones punished by the attackers.
In a siege the nobility and the garrison might come off well, as their chivalric code usually protected them, but the civilians suffered, because they were worth nothing in terms of ransoms. The poor were usually butchered. Knights would normally only surrender to another knight for fear of being killed by commoners. Such fears were not misplaced.
The chivalric code protected non-combatants, but it was difficult in a siege to differentiate between those who fought and those who did not. There are tales of besieging soldiers being killed by women throwing things from the walls onto them. Everyone within a besieged town could be considered a combatant, whether they fought or not. They had either enabled the siege to continue by feeding the defenders and assisting them in other ways, or by not attacking them.
Those surrendering unconditionally were expected to come out of the town barefoot, sometimes with ashes on their heads. Edward III’s siege of Calais was one that ended with an unconditional surrender by those inside the town.
There was a great sense of what was honourable and what was not. The breaking of one’s word was not. If a town or castle did not surrender when they said they would do so, hostages who had been given could be killed. This would usually take place close to the town walls so that its inhabitants could see their executions. It was not unusual for these to be slow and humiliating.
A town was surrendered by handing over the keys to the besiegers. Truces were generally recognised. If there was a truce, people from the town could leave it, as long as they returned at the agreed time. Hostages could be taken to ensure that the truce was kept.
Some besieging armies preferred the besieged not to surrender, so that they could make money from looting. Towns tended to be centres of wealth and plunder was a strong motivation for a medieval soldier.
Sometimes the army doing the besieging simply gave up. This might be because a relief army for the town or castle arrived and the besiegers either didn’t want to take the risk of fighting them or did fight them and were defeated. The besiegers might run out of supplies, or they might lose so many men through disease that continuing the siege was untenable.
Although there were rules about how to conduct a siege, they were interpreted with a great deal of flexibility and violence was frequently used against the besieged to ensure that the next town would surrender quickly.