The chained unicorn: a note on heraldry
Look closely at a heraldic unicorn and you will usually notice something that the storybook version leaves out: it is wearing a collar, and from the collar hangs a broken chain. This is not an accident of one artist's imagination. It is a convention, and like most heraldic conventions it is trying to tell you something.
The unicorn arrives in European heraldry in the late Middle Ages carrying a well-established set of associations: purity, ferocity, and untameability. The bestiaries insisted that no hunter could take a unicorn by strength — only by trickery, luring it to a maiden in whose lap it would lie down and be caught. A creature that powerful and that pure was attractive to anyone designing a coat of arms, because arms are, at bottom, a claim about character.
Scotland took it furthest. The unicorn became a royal symbol of the Scottish crown, appearing on the royal arms from at least the fifteenth century, and it is still there today: the Royal Arms of the United Kingdom as used in Scotland are supported by two unicorns, while the version used elsewhere pairs a single unicorn with the English lion. There is a neat old folk-logic in that pairing — the lion and the unicorn were held to be natural enemies — which later got absorbed into nursery rhyme.
A chained unicorn is a proud statement, not a sad one: this untameable thing has been mastered, and only a king could master it.
Which brings us back to the chain. A heraldic unicorn is typically shown gorged (collared) with a coronet and chained. The usual reading is that the chain advertises exactly how formidable the animal is: you only bother to chain something that could not otherwise be held. For a monarch, a chained unicorn says I have subdued a force that no ordinary power could subdue. It is boastful, not mournful. The broken length of chain in many depictions adds a second layer — the beast is so strong it has snapped its bonds, and is held now by loyalty rather than iron.
Heraldry is full of these small grammatical choices. Whether a lion is rampant (rearing) or passant (walking), which way an animal faces, what it holds in its claws — each is a word in a visual language that a medieval reader parsed without thinking. The unicorn's collar and chain are one such word. Once you have seen it, you cannot stop noticing it: on pub signs, on old bank notes, carved over doorways, that patient, powerful animal, always slightly restrained.
It is a fitting end-state for the myth, really. The wild thing that could only be caught by a trick ends up, centuries later, standing calmly on either side of a shield — tamed, crowned, and put to work holding up somebody else's coat of arms.