The local greenstone is a limestone that proved to be porous, prone to rapid deterioration when exposed to weather and a substandard building material.

The curtain wall was up to 5 metres (16 ft) thick and defended by five D-shaped towers and a twin-towered gate house.

Similar to another castle built by Ranulf during the same period at Beeston in Cheshire, Bolingbroke had no inner defensive keep.

Some design similarities are noted with the contemporary castle at Boulogne-sur-Mer, France that was also constructed without a central donjon.

Following the death of Henry of Grosmont, 1st Duke of Lancaster in 1361 Bolingbroke passed through marriage into the ownership of John of Gaunt.

[1] At the start of the First English Civil War, Bolingbroke was again put to use as a military fortification garrisoned by Royalist forces.