Crest: A dexter hand wielding a sword in bend Proper.

Motto: Aut pax aut bellum from Latin: Either peace o war 

Gunn originated from a Norse personal name "Gunni" (which means "war"). The first Gunni came to Caithness at the end of the 12th century when his wife inherited land there from her brother who was Jarl (Earl) of Orkney. Gunni's wife was descended from St Ragnvald who founded the St Magnus Cathedral in Kirkwall.  Orkney, Shetland was still part of Norway at this time.

Gunni's Viking grandfather had been killed in 1171 on a raid on Dublin.   Although Ottar, a descendant of Gunni, is known to have lived around 1280 and is the assumed progenitor of the Gunn chiefs, the first chief of the clan to be recorded with certainty was George Gunn who was the coroner of Caithness in the 15th century. He was known as "Am Braisdeach Mor" or "the great brooch-wearer" from his insignia as coroner.

A number of separate lines of Gunns became established in Braemore (known as the Robson Gunns), Killearnan, Kildonan and also the Caithness Hendersons and Williamsons. There is evidence that at the end of the 14th century Sir James Gunn accompanied Sir Henry Sinclair, Earl of Orkney, to North America, nearly one hundred years before Christopher Columbus.

The Gunns became established in the highland areas of Caithness and they were frequently in conflict with the clan Keith. This was said to be the result of the Keiths kidnapping the daughter of Gunn of Breamor in the fifteenth century who took her own life rather than submit. Towards the end of the 15th century a "battle of champions" was agreed with twelve horsemen on each side. The Keiths turned up with two men on each horse and slaughtered the Gunns. Among the dead were the chief and his four sons.  The 500 year feud was finally settled in a formal Treaty of Friendship in 1978.

In the sixteenth century the Gunns came into conflict with the Sinclairs and Gordons but strengthened their position by marriage to the sister of the chief of the clan Mackay. The Gunns did not become involved in the 1715 Jacobite Uprising and in the ’45 fought on the side of the Hanoverian government. The Gunns suffered greatly as a result of the Highland Clearances. The direct line of the chief ceased in 1821.