wer
or broch,[7] a fact which goes far to prove that the brochs, with
which we shall deal later on, existed in Roman times.[8]

As the Romans never occupied Sutherland or Caithness or even came near
their borders, their inhabitants were never disarmed or prevented
from the practice of war, and thus enfeebled like the more southerly
Britons.

After the departure, in 410, of the Romans, St. Ninian sent his
missionaries over Pictland, but darkness broods over its history
thenceforward for a hundred and fifty years. Picts, Scots of Ireland,
Angles and Saxons swarmed southwards, eastwards, and westwards
respectively into England, and ruined Romano-British civilisation,
which the Britons, unskilled in arms, were powerless to defend, as the
lamentations of Gildas abundantly attest.

In 563 Columba, the Irish soldier prince and missionary, whose Life
by Adamnan still survives,[9] landed in Argyll from Ulster, introduced
another form of Christian worship, also, like the Pictish, "without
reference to the Church of Rome," and from his base in Iona not only
preached and sent preachers to the north-western and northern Picts,
but in some measure brought among them the higher civilisation then
prevailing in Ireland. About the same time Kentigern, or St. Mungo,
a Briton of Wales, carried on missionary work in Strathclyde and in
Pictland, and even, it is said, sent preachers to Orkney.

In the beginning of the seventh century King Aethelfrith of
Northumbria had cut the people of the Britons, who held the whole of
west Britain from Devon to the Clyde, into two, the northern portion
becoming the Britons of Strathclyde; and the same king defeated Aidan,
king of the Scots of Argyll, at Degsastan near Jedburgh, though Aidan
survived, and, with the help of Columba, re-established the power of
the Scots in Argyll.

About the year 664, the wars in the south with Northumbria resulted in
the introduction by its king Oswy into south Pictland of the Catholic
instead of the Columban Church, a change which Nechtan, king of the
Southern Picts, afterwards confirmed, and which long afterwards led
to the abandonment throughout Scotland of the Pictish and Columban
systems, and to the adoption in their place of the wider and broader
culture, and the politically superior organisation and stricter
discipline of the Catholic Church, as new bishoprics were gradually
founded throughout Scotland by its successive kings.[10]

Meantime, during the centur