Another thing you might look out for is the castle’s main well, because that’s going to be essential. In the day-to-day living in a castle, it saves you having to go down to the river as your source of water. But in a siege, it becomes critical, because you can be hungry and last out a couple of weeks, but you can’t be thirsty.

It is one of the terrible things as a medieval historian, you do have to look into things like ‘how quickly does it take to starve to death’? I’ve looked at these questions, and you can go without food for two or three weeks, but you can’t go without water for more than two or three days. Maybe you might last a week and then that’ll be it. So you need a well, basically.

The first thing you do when you see a well is chuck a coin down to see how deep it is. And sometimes it’s a disappointing half a second and just goes splosh, but sometimes they can be jolly deep. If you go to Dover Castle, which I think is the deepest in Britain, and you toss a coin down there, it’s a good seven to eight seconds before you hear it go splosh. It’s incredibly deep.

The thing to think about there is just what an incredible feat of engineering that is. It gives the lie to the idea that the Middle Ages was somehow crude in terms of their engineering skills.

• Watch now | Five British castles with romantic histories

The entrances to early castles – those of the 11th and 12th centuries – are to a large extent, unimpressive. I’m not talking about the entrances to the towers, but the outer walls. Getting in through those is sometimes, literally, just a hole in the wall. Other times it’s a tower with a gateway through it.

From around about the year 1200, you start seeing two towers pushed together. That’s your twin-towered gatehouse, and the entrance is between the two towers.

By this stage they’ve got all the elaborate tricks that you associate with castle defences. You’ll have arrow loops all around, facing forwards and crossing the entrance so you’ve got a field of fire against potential intruders. As you go through the twin-towered gatehouse, if you look up or look to the side, you will see grooves in the walls for portcullises to be lowered and slots in the ceiling for them to disappear into.

You’ll almost certainly, again if look up, see holes as you go through the entrance passage, which are so-called ‘murder holes’, from which you would traditionally chuck boiling oil, but pretty much anything you like that’s nasty: quick lime or boiling water for instance.

We’re certainly beyond 1200 if you see a twin-towered gatehouse. It’s a good marker of the later Middle Ages.

• Read more | Who was the original king of the castle (and who was the dirty rascal)?

4

Putlog holes

Putlog holes are literally holes in which you put logs. They are holes in the masonry where the original scaffolding was.

This sounds like a builder not finishing the job properly, but because these buildings were whitewashed and plastered on the outside or painted over, rather than taking the scaffolding down and then filling the hole with a block, they often just sawed off the log and left it in situ.

Often these putlog holes are at a horizontal level, so they are just a line of holes for a platform. In some cases – such as in Edward I’s castles in north-west Wales – the putlog holes on the towers spiral around, as if there had been a helter-skelter effect. This is one of the things that indicates that Edward I’s castles in this area were built by continental Savoyard masons, rather than English ones.

• Read more | Reassessing Edward I: battle-hungry aggressor or dutiful conqueror?

5

Machicolations

Machicolations are where the wall head, the fighting platform, is built out from the wall so that you could theoretically throw things down on people’s heads. I think one of the reasons that people like machicolations going into the 14th and 15th centuries is because they look pretty. The way you make your castle look like it’s permanently wearing a crown is to machicolate the towers.

The earliest examples are from the 1280s on the castles Edward I built in north-west Wales, but by the time they catch on, it’s well into the 14th and into the 15th century. So if you see machicolations around the top of your towers, you know you are dealing with a late medieval castle.

• Read next | 9 of Britain’s best castles

Dr Marc Morris was speaking to Charlotte Hodgman on the HistoryExtra podcast, answering listener queries on history of British castles as part of our Everything You Wanted to Know podcast series. Hear more from this conversation in the full audio episode or explore more of our bitesize history videos.

---