|Grid reference||grid reference|
|Type||Motte and bailey|
|Events||First Barons' War|
This was originally a motte and bailey castle with a timber structure built by Winemar, the Flemish Lord of Hanslope in the 11th or 12th Century. It was at that time known as Hanslope Castle. The castle was destroyed in 1215 by Faulkes de Breauté during the First Barons' War and was never rebuilt.
Today only the earthworks remain.
Castlethorpe Castle stood in the village of Castlethorpe, which was part of the manor of Hanslope in mediaeval times. It is situated to the north of Milton Keynes, Buckinghamshire.
Castlethorpe Castle belonged to lord of Hanslope and was constructed in the 12th century, or possibly slightly earlier. In 1066 William I granted the manor of Hanslope to Winemar the Fleming, who built the fortifications. In 1086 it was in the hundred of Bunsty and ownership was the same. During the reign of Henry I it was the baronial castle of Winemar's descendant William Mauduit, chamberlain to the king. During period known as The Anarchy (1138–1153) the Mauduit family, who owned the castle at that time, supported Empress Matilda against King Stephen.
In disputes between King John and the barons, Robert Mauduit sided with the barons against the king. In the autumn of 1215 Faulkes de Breauté, general of King John, attacked the castle and destroyed it, taking the manor of Hanslope. Although Robert Mauduit eventually regained the manor the castle was never rebuilt.
The site consists of 36-foot (11 m) high motte (large mound of earth) with a timber keep on top. This is on the south of the inner bailey (flat enclosure) of 4 acres (16,000 m2), which is surrounded by an outer bailey and ditches up to 60 feet (18 m) wide and a bank. The family probably lived in hall within the inner bailey, which has entrances on the west and northwest, and there are signs that there were extensive buildings on the site