In the days when the English countryside was ploughed by heavy shire horses rather than tractors, and goods were transported by carts rather than lorries, horse brasses were something seen outside, sparkling and shining in the fields, rather than tacked up all over houses that strive for that faux-traditional Olde English country style.
What are they? Just heavy metal amulets that were hung on the horses' harnesses for decoration and to ward off the evil eye. Most of them are round, a couple of inches in diameter, and usually with a flat bar across the top so they would sit neatly on the leather straps. Although there are around 2000 known designs, the majority are simple circles (to represent the sun) crescents, hearts and stars.
Although they are thought to have strong Romany influences, there's no direct line that can be traced to them. The oldest Similar amulets were found in Siberia, buried in 2000 year old graves in the Altai mountains, adorning the frozen mummified corpses of seven horses. More commonly, they are known from about 550 AD, during the time of Emperor Justinian, but their first recorded appearance in England dates back to a print from 1685.
The growth in production and use of brasses in the 18th Century lead to a change in manufacturing methods, with production switching from hand made brasses (with flat sheets of latten brass, cut to the right design, and then shaped with hammering) to cast brasses in 1825. Foundries all over the country went into production, with a concentration of makers around Walsall.
These were made by pressing a group of wooden designs into foundry sand, joined together with a shallow depression to allow the molten metal to flow from one to the next. The metal was then poured in, and left to cool, before trimming, finishing and polishing. (The metal that joins the individual brasses at the hanger is known as a get and is usually trimmed away during finishing.)
Stamped horse brasses were produced between 1880 and the end of the First World War. It was an expensive method, requiring a metal die, and very few manufacturers produced them in this way.
Designs became more complex over time, stretching beyond the usual set of simple shapes to include heraldic patterns, traders' motifs, and special commemorative medals.
These days, with so few working shire horses around, the majority of horse brasses decorate country houses or pubs. People collect them obsessively, even modern ones.
There is no excuse for this behaviour.
If you must have them, then one, just one above the kitchen door to keep the wild roving superstitions out, is plenty. If you've never met a shire horse, then you have no forgiveness even for this token brass.