After these preliminary notes, we may now again glance at the Scots, who were destined, from small beginnings, by a series of strange turns of fortune and superior state-craft, in time to conquer and dominate all modern Scotland north of the Forth, then known as Alban. The Scots, as already stated, had come over from Ulster and settled in Cantyre about the end of the fifth century, and for long they had only the small Dalriadic territory of Argyll, and even this they all but lost more than once. At the same time, after 563, they had a most valuable asset in Columba, their soldier missionary prince, and his _milites Christi_, or soldiers of Christ, who gradually carried their Christianity and Irish culture even up to Orkney itself, with many a school of the Erse or Gaelic tongue, and thus paved the way for the consolidation of the whole of Alban into one political unit by providing its people with a common language. But in order to live the Scots had been forced to defeat many foes, such as the Britons of Strathclyde, whose capital was at Alcluyd or Dunbarton,[16] the Northumbrians on the south, and the Picts of Atholl, Forfar, Fife and Kincardine, which comprised most of the fertile land south of the Grampians. The great Pictish province of Moray on the north of the Grampians, however, remained unsubdued, and it took the Scots several centuries more to reduce it. It was when the Scottish conquests above referred to were thus far completed that the new factor, with which we are mainly concerned, was introduced into the problem. This factor was, as stated, _the Northmen_. CHAPTER III. _The Early Norse Jarls._ It was in the reign of Constantine I, son of the great Pictish king, Angus MacFergus, that the new and disturbing influence mentioned above appeared in force in Alban. Favoured in their voyages to and fro by the prevailing winds, which then, as now, blew from the east in the spring and from the west later in the year, the Northmen, both Norsemen and Danes, neither being Christians, had, like their predecessors the Saxons and Angles and Frisians, for some time made trading voyages and desultory piratical attacks in summer-time on the coasts of Britain and Ireland, and probably many a short-lived settlement as well. But as these attacks and settlements are unrecorded in Cat, no account of them can be given. In 793 it is on record that the Vikings first sacked Iona, originally the centre of Columban Christianity but then Romanised, and they repeated these raids on its shrine again and again within the next fifteen years. Constantine thereupon removed its clergy to Dunkeld, "and there set up in his own kingdom an ecclesiastical capital for Scots and Picts alike,"[1] as a step towards the political union of his realm, which Norse sea-power had completely severed from the original home of the Scots in Ulster.