Castle Park Heritage Part 4: Simon de Senlis
Between 1093 and 1100, Simon de Senlis and his wife, Maud, founded the Priory of St. Andrew's, Northampton in what is now known as Semilong, to the north of the park.
Northampton Castle was built, possibly by Simon de Senlis around the late 11th to early 12th centuries. Archaeologists remain divided about its exact position and size because the castle evolved over time. Castle Hill mound has been suggested as the site of an early motte.
A small, raised hill or mound in the centre of a castle surrounded by a walled courtyard with a protective ditch.
Archaeologists have also argued that parts of the old castle site were rebuilt or strengthened during the civil war. In the 1960s, archaeologists dug in the area and found old ditches from medieval times that had filled with dirt. It is thought that this material may have been used in the civil war to make a gun emplacement to defend the approach to the North Gate of the castle.
A specially prepared position designed to hold and fire a weapon.
If the castle was joined to the town walls when it was first built, those walls would have been part of the old Saxon defences. A map from 1610 shows the town walls, which had been rebuilt in the 12th century.
Last updated 17 October 2025