The Icelandic farm animal breeds were imported around year 874, and in the first couple of hundred years after that.  The settlers were mostly vikings and their families and workers, coming from Norway.  The horses, sheep, dairy cows and goats have been isolated here ever since, they’re old and hardy breeds, efficient in their work or production, well suited to the nature and farming in Iceland.  There is just one breed of each, the Icelandic horse, the Icelandic sheep, the Icelandic dairy cow and the Icelandic goat, and import is forbidden of more animals of these breeds, to prevent against import of dangerous diseases from other countries.  So, if you see f.ex. a horse in Iceland, you can be sure it’s of the breed Icelandic horse 🙂  The Icelandic dog breed is the same, imported at the settlement time, is an old breed and was isolated here, but now import of other dog breeds has been allowed for quite a long time.

Here on the links you can find more information about the Icelandic farm animal breeds.