Just east of Penpont House - five miles west of Brecon, and a stone’s throw from the A40 - is a field known as ‘Cae Castell’ or ‘Castle Field’.

On early Ordnance Survey maps the spot is marked with an ornate cross and the word ‘Castle’ in gothic type. Old documents refer to it as ‘Castell Einion Sais’. However, as you can see from the photograph, there is no trace of a castle, or indeed anything out of the ordinary. So what was here? And who was Einion Sais?

We know that, despite his nickname ‘Sais’ (‘English’), Einion was a Welshman of noble ancestry. He was descended from Bleddyn ap Maenyrch, the last ruler of the Welsh kingdom of Brycheiniog. Einion’s descendants were important too – they included Sir Dafydd Gam who fought and died at Agincourt, and the Games family, one of the most powerful dynasties in early modern Breconshire. Einion himself is more of a mystery. His nickname suggests he had spent time in England, or could speak English but, beyond that, only two documents refer to him directly, both from the 1270s. This was a time when Llewelyn ap Gruffudd of Gwynedd was trying to extend his power into South Wales. Not all Welshmen in Breconshire were happy about this and Einion was one of a number of powerful men of Welsh birth who opposed him. Traditionally, historians of the borderlands of Wales have focussed on the Anglo-Norman marcher lords and ignored those of Welsh descent, but recent research has seen powerful Welshmen such as Einion Sais begin to emerge from the shadows.

The last remains of Einion’s ‘castle’ were cleared away around the 1780s when the grounds of Penpont House were re-landscaped in the fashionable naturalistic style. This was done so effectively that only the slightest unevenness is visible on the ground. However, the Welsh government recently made laser-scanned LiDAR data for all Wales publicly available, which has the ability to record the land surface in great detail. While processing this data for a different project nearby, archaeologist Jennifer Muller, of Heritage in Place, noticed signs of a possible square moat on the site of the castle.

Archaeologist Jennifer Muller will lead magnetometry surveying of the suspected castle site
Archaeologist Jennifer Muller will lead magnetometry surveying of the suspected castle site (Jennifer Muller)

Now, Jennifer will lead a community archaeology project to examine the site further using ‘no-dig’ geophysics technique. The project is organised by the Brecknock Society with funding from Bannau Brycheiniog National Park’s Sustainable Development Fund. Teams of community volunteers will help investigate the site, at the same time getting hands-on experience of modern archaeological techniques. They will be hoping to confirm the presence of a moat, and to see if there is evidence for other features, such as buildings. Any additional information will not only help us to understand more about this site, but also about the other dozen or so moated sites in Breconshire, about which relatively little is known.

The work will take place on Wednesday, August 5 and Thursday, August 6. The site will be open to the public to drop in and watch what is happening between 10am to 4:30pm on both days. There is no need to book. There will be an information pavilion with displays about the project as well as volunteers to chat to. At 4.30pm on Thursday there will be a short presentation of initial findings in Penpont Stables.

All are welcome to come along and find out more about this fascinating project.

The site is about 5 miles west of Brecon, just off the A40. Turn onto the main drive of Penpont House and you will very soon see signs for parking. (Don’t rely on satnav for the last part of the journey. Make sure you turn down the front drive on the Brecon (east) side of Penpont and not the back drive on the Sennybridge (west) side.) ///range.admire.intensely

Founded in 1928, Brecknock Society and Museum Friends promote the history and culture of the historic county of Breconshire: www.brecknocksociety.wales

Bannau Brycheiniog’s Sustainable Development Fund supports projects that help improve quality of life in communities – protecting and enhancing the local environment, helping people to live healthy and fulfilled lives now and in the future.

For more information, see: Sustainable Development Fund | Brecon Beacons National Park Authority: https://beacons-npa.gov.uk/communities/substainable-development-fund/

The project will be run with the support of the Penpont Estate www.penpont.com and the Action for Conservation charity www.actionforconservation.org