The Sleaford Castle Project

Initial survey and investigatory work has already started on proposals to raise the profile of Sleaford’s Castle site, establish its history and to make better use of this important feature of the town’s heritage.

This five year project involves the Civic Trust, the Town Council, local schools,  historians and others in a collaborative effort that is expected to take 5 years. Initial funding of £10,000 has been secured for surveys and research.

Sleaford Castle Updated


A small scale geophysical survey was completed on 21/22 June 2019. This formed part of an educational programme involving local schools. Heritage Lincolnshire Archaeological Project Services, funded by Historic England, undertook a Resistivity Survey followed by a Ground-Penetrating Survey. The areas covered included the potential edge of the Bailey and some wall and footing remains.

Though small scale, the results are promising and have encouraged the Group overseeing the project, on behalf of Sleaford Town Council, to move ahead with a full survey of the site. It is intended to complete the Resistivity Survey during the week starting 17 February 2020. This coincides with our schools’ half term holiday and we hope it will encourage local engagement. Further details will be advertised through the press in the New Year.

Subsequently, the Group aspire to hold a Symposium at a local school venue to present the results of the surveys, have input talks and discussions from local experts, and to include our two local universities. The longer term intent is to apply for permission for archaeological explorations to more fully confirm and inform our knowledge of the castle, which is contemporary with that at Newark.

At the Symposium, date and venue to be confirmed, the Group will seek input from those attending about longer term developments and enhancements for the site.

Anthony Brand, History Research Lead
12 December 2019

Sleaford Castle Project summary and Latest news

The Sleaford Castle Heritage Group, formed from the Sleaford & District Civic Trust and Town Council has been working to uncover the hidden secrets of Sleaford Castle.  The aim being to develop and enhance the Castle as an important heritage asset for the Town of Sleaford.  There is no doubt that it is already an interesting and evocative historic site.

The Norman castle on this site was built by Bishop Alexander de Blois of Lincoln nearly 900 years ago.  Although fortified, the principal use was as a centre for the administration of the bishop’s land and as a residence when required.  Two prominent English Kings are known to have visited: King John in October 1216 after his disastrous crossing of the Wash and just before his death at Newark, and King Henry VIII, with Queen Catherine Howard, in August 1541 during his Northern Progress.  Falling into disuse probably in the 1550’s, the structure of the castle was gradually dismantled over the rest of the 16th and 17th centuries, with stone from the castle possibly becoming a source of building material for the growth of Sleaford.

Although there exists a brief descriptions of the castle in the Middle Ages and a sketch of the state of the ruins in the 18thcentury, there is no known contemporary painting or drawing of the castle.  The illustration of the castle on the new site entrance sign is an artist’s impression of the appearance of Sleaford Castle in 1585, thirty or so years after dismantling started.  The illustration is based on the evidence to date and replaces an image which recent investigations have indicated might well be inaccurate.

Castle sign at entrance to Castle Field


In the past, there have been few attempts to uncover details of this 12th Century building.  A limited dig was carried out on the site in 1863 and a limited resistivity survey was known to have been conducted in 1993 on the southern part of the site.  To further our knowledge, the Group has undertaken the following:

August 2018, during hot and dry weather conditions, a drone aerial photographic coverage was commissioned; the results providing a good indication of the layout of the foundations of the castle and outlying buildings.

June 2019, as part of a history project, students from Carre’s Grammar School participated in a resistivity survey of the southern part of the outer bailey.

January and February 2020 an extensive survey of the site was conducted on behalf of the Group using two up-to-date, complementary methods:

Ground Probing Radar (GPR) – GPR surveys use radio pulses directed downwards into the earth that are reflected back by surfaces or buried features to a receiving antenna.  Time taken for the signal to be transmitted and returned can indicate the depth of a feature.

Resistivity Survey – using a hand carried twin-probed array, resistivity is based on the resistance of the ground against a flow of an electric current.  Buried material or foundations slow or resist the transfer of electricity.

March 2021.  Results from the surveys were impressive and discussed by experts at a (Covid-delayed) symposium held in March 2021. It was apparent that the layout and appearance of the castle may well differ from that previously thought.

February 2022.  In continuance of the archaeological investigations, an auger survey was commissioned to take borehole samples of the areas of the moats and possible fishpond.  Due to unforeseen circumstances, this survey is yet to be conducted (July 2022).

June 2021 – ongoing.  Work has been undertaken to ensure that the importance and potential of Sleaford Castle are recognised and incorporated into both the nascent Sleaford Neighbourhood Plan and the refreshment of the Sleaford Masterplan.  This has been successful and work is ongoing to assess the feasibility of the Castle Project, including providing better access and facilities to the site. This work will be in parallel with continuing archaeological investigations and the intention to conduct excavations in the future.

05 July 2022.  Sleaford Castle was officially installed as the latest addition to the Sleaford Heritage Trail.  Information about the castle, including a short talk on King John and Magna Carta can be accessed via the QR-coded plaque at the site entrance.  Also, a new signboard at the entrance to the site and featuring an image of the Castle in the late 16th century was unveiled.


Cllr Linda Edwards-Shea, Mayor of Sleaford, unveiling the new sign.                        QR-coded plaque for Sleaford Heritage Trail

Sleaford Castle Heritage Group

 July 2022

 Sleaford Castle News 2023

Feb 2023  Tin Hat Productions have produced a video at Sleaford Little Theatre to accompany the QR-coded plaque. It features a meeting of the Carre family in 1585 with the parts played by Little Theatre actors Tony Gordon (Robert Carre the elder), Craig Pakes (Robert Carre Junior) and Laura Davies (Eleanor). They discuss the castle and plans for the future while stood in the grounds of the part-demolished castle.


Robert Carre the elder was a great landowner who had bought the castle as a ruin in 1559 and oversaw much of its continued demolition and salvage. He was one of the greatest English landowners and helped fund Queen Elizabeth’s war against Spain. He lived in Carre House, Sleaford, which later became the site of the Almshouses.  Robert Carre of Aswarby, a former High Sheriff, is believed to have lived at Old Place, Sleaford. He was the son of ‘the elder’ and ‘founded’ Carre’s school.  Eleanor Whichcote was granddaughter of Robert the elder and lived at Aswarby.

The video will be uploaded in early March 2023 and can then be viewed by either using a dedicated QR code reading app, or by pointing your smartphone camera at the app.  More details on the Sleaford Heritage Trail website.

With thanks to Chris Hodgson (Sleaford Heritage Trail) and LincolnshireWorld