counter-castle

plural counter-castles

1. A castle built to secure a lord's territorial claims or to conquer the territory of a rival ruler.

   One method was to blockade the enemy fortification with a counter-castle.

   2015, Paul Hill, The Norman Commanders: Masters of Warfare 911-1135, page 200

   2 more examples

   One advantage of using counter-castles was that it allowed prosecution of the blockade with a minimum of men, leaving the bulk of the king's army free to move against other targets.

   1997, Stephen Morillo, Warfare Under the Anglo-Norman Kings, 1066-1135, page 137

   He therefore decided to construct a counter-castle near Dunster to restrict the activities of the castle's garrison, and he left the counter-castle under the command of Henry de Tracy.

   2018, Dan Spencer, The Castle at War in Medieval England and Wales