A brief history.
A different viewpoint on the development of the nail-on shoe:
Who first invented the horseshoe? The traditional view (still held by some archaeologists) is that it was invented by the Celts around 100 B.C. This view is based on the fact that they had the need (northern type horses with broad soft feet subject to wear) and the resources (a supply of iron and the skill to forge and fashion it). The Celtic horseshoe was then supposedly re-developed by the Romans to become something very closely resembling a plain modern shoe by around 200 A.D. Some museums in the UK have Celtic and Roman horseshoes on display. But is this correct and, if so, where is the evidence?
The Roman writings of the poet Catullus and others have been interpreted as indicating horses were shod, but these comments would actually seem to be similes (e.g. “feet as hard as iron”) rather than the actual presence of iron shoes nailed onto a horse’s foot. There were also supposedly two iron horseshoes with flat sole plates found at Pompeii, but modern evidence for these is scant. One problem of finding horse shoes on archaeological sites is the dating of the shoes – are they contemporaneous with the remains, or were they lost at a later time by those robbing stone or looking for valuables? Iron itself is notoriously difficult to date with any accuracy, though modern steels may contain metals not available in the ancient world, for example chromium is only found in steel from 1865 onwards. But horseshoes are made from softer iron, the same metal today as it was 2,000 years ago. Iron is a valuable resource, and just as it is recycled today, so it was in the ancient world – perhaps even more so, since early iron smelting was nowhere near as efficient as it is today. Any discarded horseshoes would be re-used or melted down rather than being thrown away, so are never available in large numbers – only those that were lost might be found. A modern iron object will certainly contain a proportion of very ancient metal, so even if methods of dating iron were developed, their reliability would be called into doubt.
So far a lot of uncertainty and a lack of definitive evidence! Does surviving ancient literature give any indication that horses were shod? A review of early Roman discourses on horse care and veterinary matters provides no written evidence for use of horseshoes whatsoever. There are plenty of references to the need for good feet, soundness and hard hooves, but not one single mention a horseshoe. The emperor Diocletian issued an edict in 300 A.D. fixing prices for everyday goods and services, including those of the mulomedicus (horse doctor), and although this contained an exhaustive list of equine services and procedures (including care and trimming of feet), it does not list anything at all relating to shoes or shoeing. A rather surprising omission if the Romans shod their horses.
The first clear written evidence of horseshoes appears in 900 A.D. in a treatise by Leo VI of Constantinople who referred to “crescent shaped irons and their nails” in a list of cavalry equipment. A book by Vegetus written in 480 A.D. on “The Veterinary Art” makes no mention of horseshoes whatsoever, so it seems highly likely that the horseshoe in its modern form was actually developed some time between 500 A.D. and 900 A.D., but other than that it is very difficult to be precise. It seems probable that initially horseshoes were not widely used initially, as there is only very limited evidence from the following years. Iron smelting became much more efficient after 800 AD, so the raw material for shoes became accessible and cheaper. William the Conqueror is recorded as bringing shoeing smiths with him for his invasion of England in 1066, and by the time of the Crusades in the 1100s, shoeing horses was a much more common practice than in previous centuries.
But where does that leave the so-called Roman and Celtic horseshoes? Some archaeologists now believe that the so called Roman shoes are actually mediaeval ones, lost when the Roman sites were “robbed” for building material – a supposition that fits the documentary evidence well, and the type of horseshoe that was once described as Celtic, is now often re-classified as 11th or 12th century.
A final parting thought: Why was the shoe invented? Common sense answers “to prevent wear of the horses foot, so it does not go lame”, and that is a very good reason, especially for a cavalry horse that is travelling a long distance, such as to fight in the Crusades. However, it has also been suggested that an iron shoe on a war horse makes it a much more formidable weapon if one is struck or trampled. This may have been its initial intention, with other advantages coming later, though there is little evidence to substantiate this viewpoint. Some Spanish Riding School movements (e.g. capriole and courbette) are clearly aimed at using the horse’s feet as a weapon, but this is a long way from being evidence for why horseshoes were invented.
So, far from being a simple story, the true origin of the horseshoe is obscured by the mists of time and not easy to determine. One thing is clear, however – it is a technology that has stood the test of time, and remained remarkably unchanged for over 1,000 years.