EVIDENCE pointing to a Norman castle moat or ditch destroyed in a devastating flood in 1236 has been uncovered at Wisbech.

An excavation carried out in January at Ely Place unearthed plant material, seeds, charred grain and charcoal fragments dating from around 1020 to 1160.

The radiocarbon dating of the material corresponds with the period before the flood and may be direct evidence of a moat or ditch destroyed by the water.

Although a 1795 plan of the castle exists, it only shows the castle as it existed at the end of the 18th Century, before the development of the area as it is today. The design and layout of the Norman castle, thought to have been destroyed by the flood is unknown.

The excavation by Oxford Archeology East expanded on investigations carried out in the library building in 2008/2009. Experts say the newest evidence added to that from the previous investigation represents a large, ditch-like feature on an alignment not previously identified or recorded.

A report says it is difficult to draw conclusions from such a restricted study area but reveals: “ However, it can be stated with confidence that the small trench investigated here when combined with the library investigations has revealed evidence of a potential Norman castle moat.

“This greatly expands the previously limited knowledge relating to the castle and its defences, or at least suggests possibilities that can be followed up by further research or future excavation.”

There was continued flooding in Wisbech during the medieval period with the area around the castle being flooded regularly and on a catastrophic basis. Rubbish and debris would have been carried around the town in the flood waters until finally resting in large dips such as the excavated ditch.

Remains recovered from soil samples indicate that the landscape surrounding Wisbech Castle was mixed with grassland, cultivated ground and weedy wasteland as the ditch sat open and unmaintained.

After being rebuilt after the flood the castle was used mainly as a prison and for bishop’s courts, it was rebuilt in he 15th Century and during the Civil War the castle was put into a state of defence.

In 1793 the castle and grounds were sold to Joseph Medworth who turned the site into a residential development of Georgian houses formed around The Crescent and Ely Place, most of which survives today.