Do you know what this is?
It’s a Roman dodecahedron. Only a little over a hundred of these have been unearthed. They are made of copper alloy, and they date from the 2nd to the 4th century AD. They are twelve-sided, hollow, and each face has a hole of varying diameter. They have been found in coin hoards, and sites of former forts.
But nobody knows what they were used for. Now, the Ancient Romans were hardly a mysterious people. They wrote things down. They built statues to commemorate things. They covered their houses in images of everything from normal daily activities to wars and gods. But the dodecahedron? Nobody knows.
Here’s some of the speculation:
Because they were found on the sites of former military forts or camps, maybe they had a military use. A weapon? Except they’re not really strong enough to be a weapon of any kind. A surveying tool for measuring distance, since Roman armies built roads as they went? Except there are no markings on them, such as we find on other Roman measuring tools, to suggest this. A sort of socket for holding tent poles together at right angles? I love this as a theory, but in practice, then there must have been hundreds of thousands of them produced, so why have so few of them been found?
Could they be religious artifacts, like some sort of fortune telling device? This is possible, although impossible to prove unless some record of it is discovered. Similarly, some scholars have suggested they might be a masterpiece, in the literal sense that they would have been made by a metalsmith in order to graduate from apprentice to a member of a collegium.
One of the most interesting theories is to do with knitting. The dodecahedron looks a bit like a more advanced version of a Knitting Nancy. The problem with this theory is that spool knitting hadn’t been invented yet. However, what if it wasn’t used for wool?
This is an Ancient Roman necklace. Note that chain.
And now check out this YouTube video showing how you can make one using a dodecahedron.
I do like this theory. It ticks a lot of the boxes. Dodecahedrons would have been expensive given they were made of copper alloy, which puts them out of the price range of your working-class knitter (who, as we already know, didn’t exist at this time). But people manufacturing gold jewellery? They would have been able to afford them. And the fact they were found with coin hoards? How do you get gold wire? From your gold coins.
But I’m not totally sold on the idea, for a few reasons. Mostly, it seems unlikely that the Romans had discovered spool knitting, but only used it for jewellery making. After all, if you could do it with gold wire, it surely would have occurred to someone you could do it with twine or string or thin rope, and boom—suddenly knitting is born. (Caveat: I know very little about the history of fabrics and wool and the like, so what seems like a logical leap to me might easily be corrected by someone who knows the subject better.)
But dodecahedrons are also geologically interesting. Because they’re Roman, but they’ve only been found in northern Europe. It’s more accurate to call them Gallo-Roman. So are the dodecahedrons something Gallic? This makes it more likely, in my mind, that they were a cultural or religious item rather than a technology. Because any technology should have spread throughout the empire. So while the gold chain idea is one of the most solid theories I've seen on the dodecahedron, I'm going to wait until the historians weigh in.
Meanwhile, I love that there are still things we are discovering about the Romans. I love that there are still mysteries that haven’t been solved yet. And I especially love the idea that, if we could travel back in time and ask, some Roman would snort, and say, “Well, isn’t it obvious? Everyone knows what they are. It’s a...”
But for now, you’ll have to use your imagination to fill in that particular blank.