Why Motte-and-Bailey Castles Were Vulnerable

Despite their early dominance (10th–12th c.), motte-and-bailey castles had critical weaknesses:

1. Flammable: Timber palisades, towers, buildings burned easily (fire arrows, Greek fire, torches).
2. No Stone Curtain Wall: Palisade offered little resistance to battering rams, picks, or mining.
3. Single Gate: One entry = choke point; if breached, no fallback.
4. Unprotected Bailey: Vital structures (hall, chapel, stables, stores) in lightly defended courtyard.
5. No Flanking Towers: Defenders couldn't enfilade attackers at walls/gate.
6. Vulnerable to Mining: Earthen motte could be tunneled under; timber supports burned to collapse mound.
7. No Moat (Usually): Dry ditch only; no water barrier.
8. Small Scale: Limited garrison, supplies, water → couldn't withstand long siege.
9. Rot/Decay: Timber deteriorated in damp climate; constant repair needed.

Replaced by stone keeps, curtain walls, round towers, concentric rings, machicolations, moats, gatehouses—evolving to counter siege artillery and mining.