rritory 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.

The Northmen n