The Folk, then, are my own creation, as is their king, Engus. But they are based on what we know of Pictish culture in Orkney. I have allowed them their own names for places and landmarks, since most of the current ones are of Norse derivation. Most of the places in this story can be found on a modern map under other titles. The Whaleback, site of Engus’s court, is the Brough of Birsay, which does bear the remains of a substantial Pictish settlement overlaid by Viking buildings. Other places on Somerled’s map are given the names his own folk bestowed on them, the old Norse names such as Hrossey and Hafnarvagr. The Kin Stone was indeed shattered by a careless hand at some point in its history. The original can be seen in the Museum of Scotland. The Great Stone of Oaths, known as the Odin Stone, is gone now, victim of an overzealous farmer. The greater and lesser stone circles still stand, and close by them you may possibly find the old howe where Eyvind and Nessa sheltered together. You can even walk up to the hollow where they sat and looked out westward, not far from the highest point of Marwick Head. You can take a ferry across to Hoy (High Island) and walk up to the Dwarfie Stane, the rock-cut tomb which so impressed that perceptive chieftain, Ulf.

The Christian brothers and their perilous journeys from Ireland were entirely real. Early monastic settlement in Orkney is well documented; Eynhallow (Holy Island) is their home in Wolfskin, but in fact they were scattered in many parts of the islands and had a strong influence on Orcadian culture.

Orkney was only half the inspiration for this story. The other half lay with the ultimate warrior of his time, the berserk. This name probably derives from berserkir, bear shirts. Another title for such warriors was ulfhednar, wolfskins. Such apparel probably marked their special status as the elite strike force of a king or nobleman.

Paddy Griffith’s excellent book, The Viking Art of War (Greenhill Books, 1995), was responsible for sparking off my interest with its insight into the nature of berserks. The common view that such a soldier was a psychotic, shield-chewing oaf who rushed naked into battle sits poorly with his depiction in the saga literature, where he is usually highly respected and, like other Vikings, pops off home to do the seeding, gather the harvest, or father a child in between his military duties. There are references to bands of berserk brothers hired en masse, and others suggesting that hallucinogenic substances or shamanistic practices may have played a part in the berserk’s ability to summon an insane, trancelike courage.