Castle defense was a comprehensive science in the medieval period. Instead of relying on a single dramatic tactic like boiling oil, defenders employed an array of strategies supported by architecture:

1. Murder Holes

Located in ceilings of gatehouses or towers, these small openings allowed defenders to drop materials—boiling water, stones, sand, or quicklime—onto attackers attempting to force doors or batter gates.

2. Machicolations

Found on parapets or projecting towers, machicolations allowed defenders to hurl objects or pour substances directly down the castle wall onto enemies at the base. They were particularly useful in defending against sappers or soldiers scaling walls.

3. Moats and Drawbridges

These slowed attackers and prevented siege engines from approaching. Moats could be dry or filled with water, and drawbridges were often the first defensive feature to be raised during a siege.

4. Arrow Slits

Also called embrasures or loopholes, these narrow openings allowed archers or crossbowmen to shoot attackers while remaining protected behind thick stone walls.

5. Defensive Fire

Defenders used flaming projectiles, firepots, or even hand-thrown firebombs made with pitch, resin, or animal fat. The Byzantines famously developed Greek fire, a substance that burned even on water, though its exact formula remains unknown. shutdown123