Therfield Castle is a probable adulterine motte and bailey castle located in the Hertfordshire village of Therfield, close to the town of Royston. Therfield Castle is also known as Tuthill.
Pottery evidence recovered from the site suggests a date of 1135-1154 for the castle’s construction, which correlates with the suggestion of Therfield Castle dating from the Anarchy.
No buildings or masonary remnants of the castle remain, only the earthworks survive. The motte, which is surrounded by a ditch which has suffered some damage, is 14 metres in diameter at its base and 8 metres in diameter at its top. It is 1.5 metres in height. The ditch that surrounds the motte is 5 metres wide at its widest and 1 metre deep. The centre of the motte has suffered some damage as it was excavated by treasure hunters in 1920.
The bailey lies to the south of the motte. During archaeological investigations into this part of the castle evidence was found of occupation of the site prior to the castle being built. A date of 1050-1100 has been suggested for this occupation.
At the time of the castle’s construction the land that it stands on was owned by Ralph of Therfield, who had purchased the land from Ramsey Abbey who owned the manor.
The castle itself was never completed, as was the case with a lot of other contemporary adulterine castles. It seems reasonable to suggest the castle was abandoned or slighted on the accession of Henry II to the throne.
Therfield Castle sits 50 metres north-west of the village’s church and can be viewed from the road.