 In the 14th century Orkney and Shetland remained a Norwegian province , but Scottish influence was growing . Jon Haraldsson , who was murdered in Thurso in 1231 , was the last of an unbroken line of Norse jarls , and thereafter the earls were Scots noblemen of the houses of Angus and St. Clair . In 1468 Shetland was pledged by Christian I , in his capacity as King of Norway , as security against the payment of the dowry of his daughter Margaret , betrothed to James III of Scotland . As the money was never paid , the connection with the crown of Scotland became permanent . In 1470 William Sinclair , 1st Earl of Caithness ceded his title to James III and the following year the Northern Isles were directly annexed to Scotland . 
