Clan Gunn (Scottish Gaelic: Na Guinnich) is a Highland Scottish clan associated with lands in northeastern Scotland, including Caithness, Sutherland and, arguably, the Orkney Isles. Clan Gunn is one of the oldest Scottish Clans, being descended from the Norse Jarls of Orkney and the Pictish Mormaers of Caithness. The traditional origin of the Clan Gunn is that the progenitor of the clan was one Gunni who came to Caithness at the end of the 12th century when his wife, Ragnhild, inherited the estates from her brother, Harald Maddadsson who was the Earl of Orkney. His wife descended from St Ragnvald, who was the founder of the St Magnus Cathedral in Kirkwall, Orkney. Gunni, whose name meant war, was allegedly descended from Viking adventurers and his grandfather was Sweyn who was killed in a raid on Dublin in 1171. Smibert, however, states that the Gunns were of Gaelic origin. Further information on the Norse origins of Clan Gunn can be found in an article written by Michael James Gunn, quoting Sir Robert Gordon's A Genealogical History of The Earldom of Sutherland from the 17th century: "Sir Robert Gordon, in researching genealogies for his work interviewed many of the heads of families in Sutherland, among them Alexander Gun of Kilearnan and Navidale, 4th Mackeamish, who died in 1655. From him he learned that Mackeamish’s family are called “Clan-Gun from one called Gun, whom they allege to have been the king of Denmarke his sone, and came many dayes agoe from Denmark, and settled himself in Catteynes.” The significance of this statement is made clear when it is remembered that, in Sir Robert Gordon’s time, the kingdoms of Denmark and Norway were united under the Danish crown. However, the ancient Gaelic sennachies described the Gunns as Lochlannaich, or Norwegians, not Danes, because at the time of their forbear’s arrival in Orkney and Caithness Norway was a separate kingdom and not united with Denmark until the Union of Kalmar in 1391.
(from Wikipedia)