Castle design assumes the enemy will reach the walls

Thursday, December 1st, 2022

The battlements along the top of a castle wall were designed to allow a small number of defenders to exchange fire effectively with a large number of attackers, and in so doing to keep those attackers from being able to “set up shop” beneath the walls:

The goal is to prevent the enemy operating safely at the wall’s base, not to prohibit approaches to the wall. These defenses simply aren’t designed to support that much fire, which makes sense: castle garrisons were generally quite small, often dozens or a few hundred men. While Hollywood loves sieges where all of the walls of the castle are lined with soldiers multiple ranks deep, more often the problem for the defender was having enough soldiers just to watch the whole perimeter around the clock (recall the above example at Antioch: Bohemond only needs one traitor to access Antioch because one of its defensive towers was regularly defended by only one guy at night). It is actually not hard to see that merely by looking at the battlements: notice in the images here so far often how spaced out the merlons of the crenellation are. The idea here isn’t maximizing fire for a given length of wall but protecting a relatively small number of combatants on the wall. As we’ll see, that is a significant design choice: castle design assumes the enemy will reach the walls and aims to prevent escalade once they are there; later in this series we’ll see defenses designed to prohibit effective approach itself.


  1. PM says:

    Fun fact: Caerphilly Castle in South Wales (, the second largest castle by area in the UK (after Windsor) had a peacetime garrison of approximately 30.

  2. Adar says:

    Krak of the Chevaliers, if you can, is a must-see in your life time. With the war there now, it’s more or less impossible.

  3. Faze says:

    In the book Beau Geste, the walls of the fort are defended by the bodies of the dead, propped up in the crenelations with their rifles.

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