A donjon is the central, most strongly built residential and defensive tower of a medieval castle. It served as the lord’s residence, store for provisions and the last refuge during a siege. In English the equivalent is generally called a “keep”; in German “Bergfried” or “Wohnturm”.
Construction features
A donjon is built to withstand a siege:
- Thick walls — often 2 to 5 metres thick, of rubble or brick faced with dressed stone
- Height — usually 15 to 30 metres, with several storeys
- Few openings — small arrow loops instead of windows, especially on the ground floor
- Raised entrance — accessed by a retractable stair or ladder on the first floor
- Vaulted lower floors — often massive barrel vaults
- Battlements — a crenellated walk on the topmost floor
Layout
From bottom to top:
- Cellar — storage of food, wine and weapons, sometimes a well or dungeon
- First floor — guard room and entrance
- Second and third floors — living and sleeping rooms of the lord
- Watch tower or wall walk — lookout and defensive position at the top
Historical development
Donjons emerged in the 11th and 12th centuries, especially in France and England. Originally square in plan, they later became round or polygonal — less vulnerable to battering rams and undermining.
In the 14th century donjons lost their defensive role and became symbolic residential towers. Famous examples in the Low Countries include the Muiderslot and Doornenburg Castle.
Related terms
- Keep
- Crenellation
- Arrow loop
- Bastion
- Fortification
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