THREAD: something in this photo of a pillbox interior took me completely by surprise and new archive research has caused a seismic shift in my evaluation of this defence work. But where is it and what's changed? #swwSussex 1/16

The oldest walls of Pevensey Castle are Roman. The Normans landed here in 1066 and further fortification was undertaken throughout the Medieval period. A gun battery watched for the Spanish Armada in 1588 and in 1940, pillboxes were constructed amongst the ruins. 2/16

The pillboxes were ingeniously camouflaged with flints set in mortar to blend them in with the Roman and Medieval masonry. In many ways, however, I think this camouflage has actually hindered study of the SWW defences at Pevensey Castle - but why? 3/16

We've been dazzled & distracted by:

1. The clever camouflage
2. A Roman fort refortitifed during a war that ended with deployment of nuclear weapons
3. Only studying the pillboxes up close from within the castle walls

We need to change our perspective. 4/16

For the past two years @payestonework have been doing an amazing job in removing vegetation and conserving the masonry at Pevensey Castle. 5/16 https://twitter.com/payestonework/status/1318157660810784768

In 2019 @EnglishHeritage and @payestonework kindly gave me access to the pillbox by the Roman east gate during the conservation work. I learned a lot from this! 6/16 https://twitter.com/sussexPillbox/status/1154828702670295040

Two key things happened in 2020 though. Firstly, new research shows Pevensey Castle's defences were far more comprehensive than we had originally thought. Secondly, my being allowed to view the pillbox on the keep up close. 7/16

I doubt anyone has been able to see inside this structure since about 1947, so the scaffolding presented a golden opportunity. The door is sealed, but I held my camera at arm's length in both embrasures. What I saw unlocks Pevensey Castle's hitherto unknown SWW history. 8/16

Looking through the SW embrasure, the camera picked up the presence of a concrete table for a Vickers machine gun (MMG); the only known weapon-specific mounting at Pevensey Castle so far. The indents and tunnel are features seen in MMG pillboxes at Rye & Cuckmere Haven. 9/16

The NE embrasure has the same design of MMG table. Note how the anti-ricochet wall is cut at an angle to assist entry. 10/16

MMG tables mean planned arcs of fire & an intricate defensive strategy we previously didn't realise. I had wondered about gaps in the defence but thought all pillboxes (-3) survived. My new research reveals 15 unrecorded defence works we never knew about in those gaps! 11/16

I presumed the keep pillbox was built as an observation post. It's listed as one in 1941 & up high it makes sense. From here, weapons cannot cover close to the castle, but MMG tables mean distant targets across the marshes. 12/16

This is when I realised the mistake of just looking at the pillboxes up close; we need to study them from a distance too. 1,000 yards away and you're in a soggy marsh with the pillbox rising up over the trees. Some cover in the landscape, but little while advancing. 13/16

A 2,000-yard radius from the castle with *estimated* arcs of fire from both embrasures; *theoretically* the arcs overlap & cover a large amount of hinterland where invaders might form up having moved off the beach. 14/16

This pillbox was on my bucket list; although I didn't get inside, enough data was gained to completely alter the 'known' history of Pevensey Castle in 1940. Thanks to @EnglishHeritage & @payestonework for allowing access! 15/16

I've created a 3D model of the pillbox from my pictures; even though not totally accurate (no measurements were taken), it's getting me thinking. There's still a lot of research to do though! 16/16