and these islands experienced the first and most long-lasting Norse influence of any part of Scotland. Shetland is some due west of Norway and in favourable conditions could be reached in 24 hours from Hordaland in a Viking longship. Orkney is further to the south-west. Some due south of Orkney is the Scottish mainland. The two most northerly provinces of mainland Scotland, Caithness and Sutherland, fell under Norse control at an early date. South of there the entire western seaboard of mainland Scotland from Wester Ross to Kintyre was also subject to significant Scandinavian influence. The Suðreyjar, or "Southern Isles" include: The Hebrides or Western Isles comprising: The Outer Hebrides, aka the "Long Island" to the west, separated from the northern Inner Hebrides by the waters of the Minch. These islands are some west of Orkney. The Inner Hebrides including Skye, Islay, Jura, Mull and Iona. The islands of the Firth of Clyde some to the south, the largest of which are Bute and Arran. The Isle of Man, located in the Irish Sea equidistantly from modern England, Ireland, Scotland and Wales The total distance from the southern tip of the Isle of Man to the Butt of Lewis, the northern extremity of the Outer Hebrides, is approximately . This entire region became dominated by Norse culture for much of the period under consideration. For example, it is likely that the Norse language became as dominant throughout the Inner Hebrides as it did on Lewis during the 10th and 11th centuries. There was also significant direct Norse influence exerted in Galloway in south-west Scotland and for much of the period, up until the 1266 Treaty of Perth, Norwegian and Danish foreign policy and the activities of independent or semi-independent Norse rulers of the above parts of Scandinavian-dominated Scotland had a powerful influence on the affairs of Scotland as a whole. History Contemporary documentation of the Viking period of Scottish history is very weak. The presence of the monastery on Iona led to this part of Scotland being relatively well recorded from the mid-6th to the mid-9th century. But from 849 on, when Columba's relics were removed in the face of Viking incursions, written evidence from local sources all but vanishes for three hundred years. The sources for information about the Hebrides and much of northern Scotland from the 8th to the 11th century are thus almost exclusively Irish, English or