If you ever want to fluster an archaeologist or tour guide while you’re exploring Scotland, ask them what a broch is (pronounced “brock”, except with a softer “ck” than you’d normally use elsewhere).
Their brow may furrow. They may adopt a slightly pained expression, purse their lips and squint into the middle distance. They may even wince.
“Aye, well, there’s the question.”
After over a century of lively argument on the matter, the true nature of northern Scotland’s most impressive Iron Age archaeological features is still a baffling mystery. Every decade, the latest apparently watertight theory has been brought tumbling to the ground by a persuasive reinterpretation of the evidence - and the mystery reasserts itself yet again.
It’s all the more ludicrous because of the wealth of evidence available. We do know that a broch was some kind of tower, ingeniously constructed with pieces of stone fitted together without the use of mortar or cement of any kind. We know this design was repeated again and again in many settlements - because even now, after two thousand years of time have wrought their usual havoc on what’s left to see, there are still over seven hundred broch remains to explore across Orkney, Shetland and the Western Isles.
Across that number (which must only be a percentage of what originally existed, factoring in the need for remote settlements to reuse stone from collapsed buildings), we know they were anything from five to fifteen metres tall, with walls up to three metres thick, with walls that sloped inwards, like modern-day cooling towers in power stations.
We know that most of them were built in a relatively short window of time, between 400 BC and 100 AD - and abandoned as a preferred architectural style after that, despite their many structural benefits.
We know that constructed today, they’d be arduous feats of engineering - that’s if someone could even be found to engineer a dry-wall structure that big, supporting walls that high and that thick, which is unlikely. But two millennia ago, they would have been absolutely colossal undertakings, comparable to the largest medieval castles (which used mortar to keep their walls together)...
And we know there were hundreds of them.
The obvious conclusion to leap to is warfare. Why not extend the castles analogy here, and paint a picture of Iron Age Scotland torn to pieces by civil war and invasions from the European continent?
If that were true, brochs fulfilled the same kind of roles as pillboxes, charting the edges of territories and showing the defensive fears of people back then? Or could it be the mark of an invading people, much the same way England’s Edward I attempted to stamp 13th-Century Wales into submission with a castle-building campaign?
There’s only one problem with this: on their own, brochs are pretty useless as defensive structures.
Let’s say you’re rushing a broch - and for the purposes of this thought experiment, let’s presume they’re standing relatively alone in the landscape (which does seem to have been the case with many excavated in Scotland, while those in Orkney were often surrounded by houses). What’s your plan of attack?
Well, take your pick. You could just climb those walls - it’s dry-stone, so there are plenty of holes to put your hands and feet into. You could shove lit branches through the holes in the wall and smoke the defenders out. There were no external windows, so there was no way for defenders to snipe at attackers with missiles (except if there was roof access). And you could just attack the weakest point in the structure with a battering ram - which, unfortunately for everyone inside, was almost always the entrance-way.
Add to this the fact that there is no archaeological evidence for fighting or the violent destruction of property at any of these sites. Not a single trace, in a century of investigation.
For these reasons, Scottish archaeologists gave up on thinking of brochs as fortresses, and more recently started considering them as the equivalent of stately homes, owned by wealthy landowners looking to show off to their neighbours in the most extravagant way possible.
But if this were true, countered other ancient historians, Iron Age Scotland would have been ridiculously, mind-bogglingly wealthy, based on the amount of time and effort that must have been spent making each broch.
It’d be like the south of England being littered with over seven hundred Buckingham Palaces. And it didn’t fit their distribution, which really does look military, clustered around defensive bottlenecks in the landscape and apparently using natural cover for added fortification.
For example, there are the remains of many substantial brochs around the entrances to the mighty Scapa Flow in Orkney - a body of water that is such a natural defensive position that it was the UK’s main naval base during both World Wars.
So how about watchtowers, less a point of defensive, more an early warning system? That would certainly explain the height of them - but again, why so many, why make them so sturdy, why so much effort into something designed to be abandoned at first sight of the enemy, and….
And so the controversy goes round and round.
Whatever the reasons behind their origins, we can at least be certain about what brochs were later turned into - which is, basically anything and everything, particularly as gathering places for communities. But at the end of the broch-building period, there are clear signs of abandonment across Scotland and the islands around it.
In just one century, most of everyone living in a broch and using it for whatever purpose we can’t quite discern...they seem to have decided that the broch’s time has passed, and then moved out, leaving the towers to be claimed for pragmatic reuse.
This is why you’re unlikely to get a straight answer to your question about brochs - because there aren’t any. Without any way to get into the heads of the ancient communities that build them, we just don’t know what they were for, and why they were built on such a massive scale.
Will we ever?
Aye, there’s the question indeed!