Soay sheep, perhaps the most primitive extant form of domestic sheep, all come from the island of Soay. The origins of the Soay sheep here are uncertain. The old Scandinavian name Sauda-ey means 'Island of sheep', so they were probably present on the island of Soay in Viking times (9th and 10th centuries AD).

The Island of Soay lies in the North Atlantic 41 miles west of North Uist in the Outer Hebrides off Scotland. It is known for its fierce winds, unpredictable weather and granite and sheer cliffs, which rise more than a 1000ft straight up from the sea, the tallest in Britain, these islands are home to the Soay sheep (Ovis aries L.), a small, primitive breed of the northern short-tailed group.

The Soay is considered by many to be the only living relic of man's earliest domesticated sheep. Its fine, short fleece gives scientists some insight into just how far Neolithic farmers had advanced in the development of wool from a short inner fleece found beneath the coarse outer hair of its wild ancestors. [Ponting, 1980]. While no one knows precisely how or when the sheep arrived on St. Kilda, archaeological evidence leads them to believe it has been there for several thousand years.

With certainty it has survived in total isolation on the uninhabited isle of Soay since historic times. For much of its past it had human neighbours on Hirta, a larger, adjacent island, but because of Soay's inaccessibility the two had relatively little contact and the sheep's evolution was driven entirely by nature and the environment and not by any form of artificial selection by man.

As a result the Soay is now a living archive of the origins of domestic sheep and an undiluted genetic reservoir for the future.