Don’t be confused by the first syllable: this English word doesn’t imply a head covering, though it can be used for clothing. But there is a historical link, as some experts believe that caparisoned ultimately derives from the Latin word for a cap.
The original caparison wasn’t for humans. It was a cloth spread over the saddle or harness of a horse. Its source — through French — was Spanish caparazón for a saddlecloth (which may also be the source of carapace, for the upper shell of a tortoise, by inversion of the p and r through what’s called metathesis). This probably came from capa, a short cape or hood, itself from late Latin cappa, a cap. Our cape is from the same Latin word, though via Provençal and French instead. The link may be the idea that a cloth on the back of a horse is equivalent to a cape for a human.
Medieval caparisons could be richly decorated, though that wasn’t implied by its original meaning. However, almost as soon as it came into English it was being used for any sort of splendid or expensive covering, including that of the person. In The Winter’s Tale Shakespeare created the confidence trickster Autolycus, the original “snapper-up of unconsidered trifles” (meaning he appropriated anything that had been left unguarded). When he appears, he wittily bemoans his caparison of rags and tatters, to which he had been reduced after too much gambling and wenching.
Caparisoned often features in historical novels, especially nineteenth-century ones by writers such as Sir Walter Scott. It has dropped off in popularity since then and has become a semi-cliché, often preceded by words such as richly, ornately and finely.
The feasts and pageants that mark coronations, births, marriages and deaths are good for juicy details. Imagine giving birth under a mink-edged cloak of velvet on a richly caparisoned pallet bed, then being removed to an even more splendid bed of state.
The Independent (London), 16 Nov. 2013.
Though caparisoned is still common, caparison (my fingers keep wanting to type comparison) is rare these days, though it can have a melancholy sense that is unrecorded in dictionaries. A symbolic riderless horse in the funeral procession of a statesman or senior soldier is sometimes called a caparison. As it was earlier on called more fully a caparison horse, this would seem to be a shortening that implicitly transferred the sense from the mourning decoration of the horse to the horse itself.
It was Lord Mountbatten’s boots that I particularly remember. They were reversed in the stirrups of his favourite black charger, Dolly, as it led the ceremonial procession at his funeral 30 years ago. The riderless horse is known as a caparison, a custom that dates to the time of Genghis Khan. It symbolises a fallen warrior.
Daily Telegraph, 10 Oct. 2009.