Not long ago, I looked at how battles in the Middle Ages were, and were not, like the battles seen in fantasy movies. Some of the most memorable on-screen skirmishes didn't involve two armies clashing in the field, however. The Battle of Helm's Deep in The Lord of the Rings: The Two Towers and the Siege of Riverrun in Game of Thrones, not to mention the Trojan War of The Iliad, all deal with fortified cities encircled by a hostile force. Were sieges really like what we see in fiction? Let's take a look...
Because a siege was such a large operation for both sides, many sieges ended without bloodshed. Either the defenders ran out of food, or the attackers did. Knights only pledged to give 40 days of service to their lord each year, so they would simply leave the attacking army when their time was up.
Most sieges finished not with open combat but with negotiation or bribery or blackmail, which spared many lives. Whether this was benevolent, shrewd, or cowardly, I leave up to you.
Laying siege to a castle was a huge investment in time and resources. HistoryNet lists some of the commodities that an attacking army needed for a successful siege: Timber, lead, tools, nails, food, drink, livestock, iron, hides, charcoal, leather, screens, bolts, hammers, mallets, wedges, tents, and wax. Food was often hard to come by because the local farmers employed a scorched-earth policy against the invaders.
Then there was the matter of protection. The attacking army sat in the open field with enemy archers staring down at them. So any sortie against the castle needed a defense. The attackers built "penthouses," mobile chambers that were wet to protect against fire and covered in iron plates to prevent arrows and crossbow bolts from coming through. Protected by these structures, attackers could use battering rams against the castle doors, or "cats"—giant claws that tore at the castle walls. The larger version of these were called siege towers, with multiple floors, that allowed for attacking upper windows or even the parapets themselves. They're visible on the left side of the illustration above.
If the castle had a moat, the attackers would try to fill it, or construct a bridge across it or a barge that could float on it. "Sappers" would dig a tunnel under the castle and then blow it up, hopefully taking portions of the castle wall with it. The attackers could then advance through the breach. This is where the term "undermine" comes from.
In a way, the army inside the castle had the easier task; they simply to had outlast the attackers. If they had enough food and water, there would be little reason to give in to the attackers' demands.
What could the defenders do while the invading army built their own defenses and weapons? They shot arrows and crossbows, of course. They would prevent any solider or siege tower getting too close by pouring hot water, flaming oil, or quicklime on them. They also dropped stones and burning straw.
If the defenders could get a message out, friendly forces could arrive and encircle the invading army, giving them no escape.
Before mounting a full assault, the invaders usually tried to soften the defenses first. For this, they used all manner of siege engines. These included:
- Catapult, which could fling stones over the walls. Also used to send diseases animals or corpses into enemy lines, in an early version of biological warfare.
- Ballista, a sort of giant crossbow that fired spears or bolts along a straight trajectory. The projectiles could impale oncoming troops.
- Trebuchet (above), a powerful weapon that could "hit targets at a range of five hundred yards with missiles exceeding three hundred pounds in weight" and could "relentlessly pound a curtain wall until it broke open," according to HistoryNet.
The defenders could use similar devices to return fire, but often they could do little but duck, hope their walls held, and conduct repairs on whatever damage the projectiles caused.
Storm the Castle!
Sometimes there was no alternative but to attack the castle, just like in the movies. At that point, all the defenders' tactics would be employed: Siege towers, siege engines, archers, sappers, and soldiers carrying ladders. The defenders would retaliate with hot liquids and archers of their own, and stand ready to fall back to interior fortifications if the outer defenses fell.
If the attacking army made it over the walls (an "escalade"), they would actually give the defenders one last chance to surrender. So very few sieges ever got to the point of fighting in the courtyards or in the chambers of the castle. Medieval commanders, for various reasons, wanted to limit loss of life, and offered every chance to negotiate a way out of conflict. Perhaps it wasn't such a barbaric time after all.