Bolingbroke Castle

Bolingbroke Castle
Part of Lincolnshire
Bolingbroke, England
The ruined walls of Bolingbroke Castle
Type	Enclosure castle
Site information
Controlled by	Heritage Lincolnshire
Open to the public	Yes
Condition	Ruined
Site history
Built	c. 1220
Built by	Ranulf, Earl of Chester
In use	13th to 15th century
Materials	Spilsby Greenstone Timber Earth
Demolished	c. 1652
Battles/wars	Battle of Winceby
Events	Birthplace of Henry of Bolingbroke

Bolingbroke Castle is a ruined castle in Bolingbroke (or Old Bolingbroke) Lincolnshire, England.

Most of the castle is built of Spilsby greenstone, as are several nearby churches. 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 castle was constructed as an irregular polygonal enclosure. The castle is one of the earliest examples of a uniform castle designed and built without a keep. It originally was surrounded by a large water-filled moat 31 metres (102 ft) wide. The curtain wall was up to 5 metres (16 ft) feet 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, Bolingroke had no inner defensive keep. The castle relied instead on thick walls and the five D shaped defensive corner towers. Some design similarities are noted with the contemporary castle at Boulogne-sur-Mer, France that was also constructed without a central donjon.

The area was first fortified by the Saxons in the 6th or 7th century. In the 12th century the Normans built a Motte-and-bailey on a nearby hill above the settlement of Bolingbroke. The present structure was founded by Ranulf, Earl of Chester, in 1220 shortly after he returned from the Fifth Crusade.

Ranulf died in 1232 without a male heir, and his titles, lands and castles passed to his sisters. Following the death of Henry of Grosmont, 1st Duke of Lancaster in 1361 Bolingbroke passed through marriage into the ownership of John of Gaunt. His wife Blanche of Lancaster, daughter of Henry of Grosmont, was born at the Castle in 1345. John and Blanche's son, Henry, was also born at Bolingbroke Castle in 1367 and consequentially was known as "Henry Bolingbroke" before he became king in 1399.