The Attacotti, Scotti, Picts, and Saxons
mentioned by the historian Ammianus are clearly mentioned as
different peoples. All of the Irish are lumped together as Scots. The Picts
are mentioned as one group. The only Germans mentioned are Saxons,
but it was common practice in Roman Britain for any encountered sea-borne Germans
to be labelled Saxons.
This all implies that the Attacotti were members of another ethnic group.
But if so, where did they come from? There are no others in the region. The only peoples
in the British Isles at this time are Germans (Saxons, Frisians, etc), Picts, Scots,
and Britons. So could the Attacotti be Britons?
Saint Jerome's Against Jovinianus mentions numerous tribes and peoples by name and differentiates
between them strongly. St Jerome says, "I myself, a
youth on a visit to Gaul, heard that the Atticoti, a British
tribe..." ("cum ipse adolescentulus in Gallia viderim Atticotos,
This was in the fourth century AD, the middle 300s,
and in that period the only Britons outside the empire (though
not outside its influence) were in the mostly abandoned region
north of Hadrian's wall, south of the Antonine Wall (and possibly
the 'lost' province of Valentia).  The tribes between the two walls at that time seemed to
have formed client kingdoms, and they knew
they needed to behave themselves or a Roman legion could appear and
take their forts.
Only one tribe or kingdom of Britons had a fort
which could not be easily reduced by the Roman engineers. This was
Alt Clut, the 'rock of the Britons'. It was on top of a high rock
with many vertical sides, and protected by water on three sides. And
it was to the north of the Antonine Wall.
If one removes the two "l" from Alt Clut, one gets
At Cut, easily simplified or mispronounced as Atcut, which would
then be Latinised as Atticoti when written in Latin. The Britons of
Alt Clut had a tradition of calling themselves the last free Britons. As such
they would resent the Roman occupation and would be willing to attack
Roman Britain to the south.
An example of this behaviour comes a century later
in the epistle to Coroticus written by a Briton known today as Saint
Patrick (see link, right, for the full epistle). In that letter
Patrick complains bitterly to Coroticus, the king of Alt Clut,
because Coroticus' soldiers attacked Patrick's Christian converts in
Ireland, murdering some, and taking captive others which were then
sold to the Picts. Patrick was a Roman Briton, and Christianity was
at that period regarded as a Roman religion to be shunned by the
pagans of the north. The original 'barbarian conspiracy' of Scots,
Picts, Saxons and Attacotti would have been an alliance of pagans
opposed to Roman Christianity.
They would appear to be the perfect candidates for
the Attacotti, Alt Clut, otherwise known at a later date as
Dumbarton, the Rock of the Britons, today