The Repository Stone Record

Rochester's Tower Fell. The Castle Did Not.

September 5, 2026 · Runtime 9:17 · Watch on YouTube

In the autumn of 1215, King John's miners dug under the south-east corner of Rochester's great tower and burned forty pigs' worth of fat under the props. The writ ordering the pigs survives, on the close rolls, dated 25 November. The corner came down. Almost every retelling stops there — the mine works, the castle falls. It did not fall. It fell five days later, to hunger, and what stood between the mine and the surrender was a wall built ninety years earlier for reasons that had nothing to do with sieges.

Chapters

  1. 0:00 The story everyone tells
  2. 1:40 What Corbeil built
  3. 2:19 The wall down the middle
  4. 4:18 How a mine takes a corner
  5. 4:35 Forty pigs, in writing
  6. 5:38 The sentence nobody quotes
  7. 5:57 What actually ended the siege
  8. 6:17 The repair bill
  9. 6:34 Three square, one round
  10. 8:14 The obituary that was wrong
  11. 8:55 The reading

Transcript

Here is the story, the way it gets told. In the autumn of twelve hundred and fifteen, King John's miners dug under the corner of this tower. They packed the tunnel with timber. Then they sent to Dover for forty pigs, and burned the fat under the props. The corner came down. And the castle fell.

Every part of that is documented, including the pigs. The last sentence is wrong. The corner came down, and the siege carried on. What beat the mine was a wall built ninety years earlier, for reasons that had nothing to do with sieges. You can still stand in front of it.

Rochester sits where the London road crosses the Medway. There has been a castle on this spur since the Normans arrived, and it has been fought over more than once. The tower everybody photographs is not the first castle here. It is not even the first stone one.

The first stone castle has a price on it, in a document. A scribe at Rochester records that Bishop Gundulf built the king a castle here in stone, entirely at his own expense. The cost, he reckons, was sixty pounds. Notice the hedge. The oldest building figure we have for this site is one its own writer would not swear to.

The great tower is about forty years later than that. In eleven hundred and twenty-seven, Henry the First handed Rochester to William de Corbeil, Archbishop of Canterbury. The condition was that he fortify it. What Corbeil put up is the thing still standing on the hill.

It is seventy feet square on the outside, about twenty-one metres. The walls are twelve feet thick at the base, tapering to ten at the top. It stands a hundred and thirteen feet to the parapet, and the turrets go twelve feet higher. It is the tallest keep in England.

You cannot simply walk into it. The entrance is upstairs, guarded by a forebuilding on the north side, and the stair to it crosses a gap nine feet wide. Everything about the approach is built to make an attacker queue. Which is a large part of why John eventually went under it instead.

And inside, it is not one room. A cross-wall runs east to west through the middle of the building, the full height of it, from the basement to the roof. It carries the floors. It carries an arcade at hall level. And it carries the well shaft, with an opening on every storey.

That wall is structure, not tactics. A tower this wide cannot roof itself in one span, so the middle wall is what makes the floors possible at all. The well inside it is convenience: water upstairs without going down to the yard. Nobody here was designing against a mine.

Skip forward eighty-eight years. In twelve hundred and fifteen the castle was in the keeping of the Archbishop of Canterbury, Stephen Langton, and King John wanted it back. Langton did not hand it over. The constable holding it, Reginald de Cornhill, opened the gates to the rebel barons instead.

The garrison was a baronial force under William d'Aubigny. Knights, their retinues, archers and crossbowmen — the counts in the sources do not agree. John arrived on the thirteenth of October. The Barnwell chronicler counted five stone-throwing engines working against the walls.

The first thing to fall was not the tower. John's men undermined the outer wall and took the bailey, and the garrison pulled back into the keep. That is a castle working exactly as intended. It is not one obstacle. It is a series of them, and each one has to be paid for separately.

For the tower he sent for specialists. Miners were brought in from the Forest of Dean: professional pit men who cut ore for a living, not soldiers. Picks were ordered made, as many as could be made. Different accounts give different numbers of miners. What is not in doubt is the trade.

A mine is not a demolition charge. The miners drove a tunnel beneath the south-east corner of the great tower, and propped the roof of it with timber. You do not dig the wall down. You dig a void under it, and then you take away the thing holding the void up.

Which is where the pigs come in, and they come in as paperwork. On the twenty-fifth of November, a writ went out from the siege to Hubert de Burgh at Dover. It is on the close rolls. It is not a story a chronicler heard later. It is an order for supplies, entered by a clerk, with a date on it.

Read what it actually says. It orders forty of the fattest bacon pigs, of the sort least good for eating, sent day and night, to bring fire beneath the tower. That is a request for fuel. It is not a report of a collapse. No single document in this story does both, and that is worth saying out loud.

The collapse itself is not in doubt. The fire took the props, the void closed, and the south-east corner of the keep came down. In the popular version of this siege, that is the last event. The castle falls, John wins, and the story ends in a cloud of dust. It does not end there.

The Barnwell chronicler wrote the next sentence, and almost nobody quotes it. The garrison did not surrender. They went through the doorways in the cross-wall, into the northern half of the tower, and shut it behind them. Half the keep was rubble. The other half was a castle.

What ended it was food. Conditions in the standing half got worse by the day, and the garrison were reduced to eating their own horses. They surrendered on the thirtieth of November. The writ for the pigs is dated the twenty-fifth. The mine bought John the last five days of a seven-week siege.

Now the part that is not in the chronicles at all, because it is in the accounts. Between twelve seventeen and twelve thirty-seven, the Crown spent about six hundred and eighty pounds repairing Rochester. Five hundred and thirty of that went into the great tower alone.

Work on the keep probably starts around twelve twenty-six. It is mostly done by the following year, and continues to twelve thirty-two. And the south-east corner does not come back the shape it was. Three corners of this building are square. The fourth one is a cylinder.

The usual explanation is mining. A square corner gives a miner two faces to work and a quoin to lever out. A cylinder gives him neither. That reading is probably right. It is also an inference. The rolls record what the Crown spent, not what the Crown was thinking when it spent it.

And Rochester did not invent it. The round tower was ordinary practice long before John's miners arrived. Conisbrough went up cylindrical in the eleven-eighties. Philip Augustus was standardising round towers by about eleven ninety. Pembroke's round keep was begun in twelve hundred and one.

Call it a scar if you like, but be precise about the kind. It is not the wound. It is the repair, done to the standard of its own moment. The keep John attacked was already ninety years old and built to an older pattern. That corner is the thirteenth century patching the twelfth.

It did get tested. In April, twelve sixty-four, in the next civil war, Simon de Montfort and Gilbert de Clare broke into the bailey and could not take the keep. Be careful with that, though. The siege was lifted because a relieving army was coming, not because the walls won.

Which brings us back to the chronicler. His line about Rochester is the most quoted sentence about the whole siege. Our age has not known a siege so hard pressed, nor so strongly resisted. And then: afterwards, few cared to put their trust in castles. It gets read as an obituary for the castle.

The people who paid the bills disagreed. Within about a decade the Crown was putting five hundred and thirty pounds back into this one building. And it rebuilt the broken corner in the current shape. A chronicler wrote that castles were finished. A clerk wrote otherwise, in cash.

So that is the reading. The mine took a corner. The cross-wall took the mine. Hunger took the castle. Next time, an account roll that stops in the middle of the job. Kirby Muxloe, in Leicestershire, where the building accounts survive week by week, and the brickwork stops at the height they do.

Description and sources

Rochester's keep was raised around 1127 by William de Corbeil, Archbishop of Canterbury: seventy feet square, walls twelve feet thick at the base, the tallest in England. Running east to west through the middle of it, the full height of the building, is a cross-wall carrying the floors, an arcade at hall level and the well shaft. Structure, not tactics — a tower that wide cannot be roofed in one span.

In October 1215 the barons who had forced Magna Carta on King John held Rochester against him. His men took the bailey, then mined the keep's south-east corner, and on 25 November he sent to Dover for forty of the fattest bacon pigs, of the sort least good for eating, to bring fire beneath the tower. The corner came down — and the siege carried on. The garrison went through the cross-wall into the standing half and held it until the food ran out, surrendering on 30 November having eaten their horses.

The round corner every visitor photographs is not the wound. It is the repair: of the roughly £680 the Crown spent here between 1217 and 1237, £530 went into the keep alone, and the corner came back as a cylinder — ordinary practice by then for thirty years. Which leaves the same chronicler's famous line, that after Rochester few cared to trust in castles, disagreeing with the exchequer. One of the two was paying.

PRINT-READY, FROM THIS CHANNEL

How to Read a Castle, Vol. 01 — the method, the measured drawings and the documents behind the first two episodes

https://therepository.gumroad.com/l/read-a-castle

PRIMARY SOURCES

ARCHIVE PLATES — public-domain documents, with author, date, archive and licence.

... and 13 more plates, each credited on screen in the video and listed in this project's manifest.

Stone Record reads castles as documents — what the surviving paperwork and the standing masonry actually say, against what gets repeated. Primary sources are linked above.

Every historical image here is public-domain material from Wikimedia Commons, credited on screen — nothing in this video is AI-generated. Views of Rochester by the Buck brothers (1735), Skelton (1757), Serres (1783) and Dayes (1799), a Rijksmuseum albumen print of the 1860s, a 1904 postcard, and public-domain photographs. The plans, timelines, cost comparison and document panels are drawn in code from the figures named on screen; the keep plans are schematic, from published dimensions.

#castles #medievalhistory #england #magnacarta #siegewarfare