In 844, Kenneth, king of the Scots, the small North Irish sept which,
as stated above, had crossed over from Erin and held the Dalriadic
kingdom of Argyll with its capital at Dunadd near the modern Crinan
Canal, succeeded in making good his title, on his mother's side, to
the Pictish crown by a successful attack from the west on the southern
Picts[2] at the same time as their territory was being invaded from
the east coast by the Danes. Thereafter, these Picts and the Scots
gradually became and ever afterwards remained one nation, a course
which suited both peoples as a safeguard not only against their
foreign foes the Northmen, but also against the Berenicians of Lothian
on the south. With the object of ensuring the union of the two peoples
Kenneth is said to have transferred some of the relics of Columba, who
had become the patron saint of both, from Iona to Dunkeld, which thus
definitely remained not only the ecclesiastical capital of the united
Picts and Scots, but the common centre of their religious sentiment
and veneration. Incidentally, too, the Pictish language gradually
became disused, as that people were absorbed in the Scots; and
unfortunately, through the fact that no written literature survived to
preserve it, that language has almost entirely disappeared. The better
opinion is that it was more closely akin to Welsh and Breton than to
Erse or Gaelic, the Welsh and the Picts being termed "P" Celts, and
the other races "Q" Celts, because in words of the same meaning the
Welsh used "P" where the Gaelic speaking Celt used the hard "C". For
instance, "Pen" and "Map" in Welsh became "Ken" (or Ceann) and "Mac"
in Gaelic.[3]

In the reign of Constantine II, Kenneth's son and next successor but
one, further incursions by the Northmen took place under King Olaf
the White of Dublin in 867 and 871; while in 875 his son Thorstein the
Red, by Aud "the deeply-wealthy" or "deeply-wise," landed on the north