One of the most fascinating aspects of the Icelandic Horse is that it has remained a true pure breed for over eight hundred years. Over the centuries, the horse has adapted to this famously harsh environment and has also changed due to selective breeding, having always lived both in partnership with man and running free in the wild. While it might seem that a totally isolated breed would run the risk of the dangers of inbreeding, the Icelandic Horse has not only survived, but thrived under such difficult conditions.
When Iceland was settled at the end of the ninth century until the beginning of the tenth, the settlers brought with them their livestock, including their horses. Mostly made up of Dole Horses from Norway and Celtic Ponies from the British Isles, the horses were not only an important part of daily life but became revered according to Norse religion. Very quickly, the horses had to adapt to the widely varying environment of Iceland, tolerable in the summer but unbelievably cold and unforgiving in winter, not to mention active volcanoes and a difficult terrain. But the Icelandic Horse was also relied upon for a wide variety of work. Up until the end of the 19th century, the horse was the only reliable means of transportation, whether it was under saddle or driving a cart. They were also used as pack horses and farm horses.
The traditional body type of the Icelandic Horse for many years was quite short, very stocky and extremely hairy. All of these factors helped the horse survive in the harshest of environments. Nature did its work to cull those horses that weren't able to withstand the worst weather or volcanic events. The most prominent example is the terrible weather that happened in 1783. At the time there were approximately 32,000 horses in Iceland; the following year there were only 8,600. All of today's Icelandics are descended from these survivors. The horse also tended to stock up on food in the summers because of the lack of available food in the winter, so they went from quite fat to lean during the course of the year.
In more recent years this has changed, thanks to more participation from man in selection and winter care. In the distant past, the horses were forced to fend for themselves in the winter in times that man could barely care for himself, but now horses are able to be fed throughout the year. Now that Icelandics are being fed the year round, they are growing slightly taller but their metabolisms haven't changed. The horse has also developed very strong hooves, thanks to the roughest of terrains, and because they have no natural predators in Iceland, a very intelligent disposition. This is a horse that rarely bucks or kicks and often stops to think through a situation when faced with an obstacle.
It has been widely reported that imports of horses have been banned for eight hundred years, but there is no evidence that supports this. It is more likely that imports were simply not needed in the early centuries after settlement. However, importing horses was banned in 1882, but this was done more for the protection of the breed's health than for its purity. Because the horse has been isolated for so long, the breed has never encountered some of the diseases that have become common for other breeds around the world. Importing one horse could potentially spark an epidemic that could destroy the entire breed. This rule is taken to seriously that any Icelandic Horses that leave the country are never permitted to return.