 In 1231, an unbroken line of Norse earls of Orkney ended and the title was since held by Scottish nobles.An ill-fated expedition by Haakon Haakonarson later in that century led to the relinquishing of the islands of the west to the Scottish Crown and in the mid-15th century Orkney and Shetland were also transferred to Scottish rule.The negative view of Viking activities held in popular imagination notwithstanding, Norse expansion may have been a factor in the emergence of the Gaelic kingdom of Alba, the forerunner of modern Scotland, and the trading, political, cultural and religious achievements of the later periods of Norse rule were significant.