Between AD 468-469, a man described as the king of the
Britons crossed the English Channel to Gaul, bringing 12,000 ship-borne
troops with him.
This 'king', Riothamus, remained in Gaul for a year
or more, advancing to Bourges in central Gaul, and even beyond. He
teamed up with other parties who were interested in maintaining imperial
order in Gaul against the growing threat presented by the Visigoths in
Hispania and southern Gaul. However, Gaul's imperial prefect, the deputy
of the Western Roman emperor, treacherously undermined him by dealing
with the Visigoths.
A battle ensued near Bourges in 469 between the Britons
(possibly bolstered by units of Armorican Bretons), and an overwhelming
force of Visigoths. The Britons were eventually defeated when no imperial
forces came to their assistance, thanks to the treachery of the prefect.
Riothamus escaped with the remnants of his army into the nearby territory
of the Burgundians, never to be heard of again.
The imperial forces, which consisted of a combined army
of Romans, troops from Soissons under Comes Paulus, and Burgundian
foederati, were subsequently defeated in a second major battle.
Paulus was probably killed, and Soissons and Armorica were now cut off
from Rome, never to be regained.
Riothamus the Briton or Breton?
The identity of Riothamus has always been a
The events of 468-469 were recorded reliably
enough, but with the 'king's' identity somewhat obscure. Until
recently most historians have labelled him a Breton, one of the
British migrants in Armorica (modern Brittany), and have dismissed
the event as a relatively unimportant Breton attempt to be a player
in Gaulish politics of the fifth century.
The available evidence, though, does not specifically
state that he was a Breton .
True, there is a 'Riotham' in the lives of some of
the Breton saints. He is claimed as the son of King Deroc of Dumnonee,
although the 'Lives' state this is Deroc II while other evidence says
that he is the grandson of Guitol (father of Deroc I). According to
that evidence, he is exiled to Britain following the death of his
father, but he eventually returns and kills the usurping general
who has taken his inheritance. This either makes him a contemporary
of or the same man as Riothamus, or someone from a couple of
generations later in time who had been named in his honour.
Those who relegate Riothamus to being a more minor
Armorican prince tend to ignore the fact that he travelled by sea to
reach Gaul, which he certainly wouldn't have had to do to get there
from Armorica. It seems much more likely that he was a British
leader (whatever his origins), one who, perhaps, had largely pegged
back the Saxon and Jutish threat in Britain itself by this time .
His expedition is very much in the tradition of
Magnus Maximus, Constantine III, and even various Roman usurpers of
previous centuries in Britain. All of them withdrew troops from
Britain to fight in Gaul. All of them were ultimately defeated,
although in the case of Riothamus, it is not certain that it was due
to the treachery of the prefect of Gaul. This official, one Arvandus,
had sent a message to the Visigoths stating that the Britons beyond
the Loire should be attacked, meaning either Riothamus and his army,
or the Armorican Britons in general. The chronology is open to
interpretation, and Arvandus could have been arrested and shipped to
Rome before the arrival of Riothamus. But either way, the threat to
British interests was a very real one.
With slight spelling variations (Riotimus, Riutimus,
Riatham), this mysterious British leader is referred to by Continental
writers as not only the king of the Britons (Jordanes) but as Riothamus.
Something that has only been realised more recently is that this is
not a name. It Latinises a title or honorific in the British language,
Rigotamos, in much the same way as as 'Vortigern' is a title
rather than a name. This particular title meant something along the
lines of 'supreme king' or 'supremely royal'. This is far from unique
in history, with a much more famous example being Genghis Khan, which
means 'Very Mighty Ruler'.
Edward Dawson points out that while 'Rio' as a
shortened form of 'Rigo' ('king') is exactly right, the next element
appears to be an unrecorded cognate of the Latin 'dominus' or 'domno',
which means 'master' or 'lord'. In this case it would mean the high
king, or the lord of kings. The element also occurs in a royal name
among the Catuvellani tribe of pre-Roman Britain. Togodumnus was
literally Lord Dagda, a deity-based name.
A later look at the same name produces an
alternative theory, though. Very early the Britons dropped the 'x'
sound from words, so that Saxon became Saison, for instance. In this
manner, the Celtic 'rigo' or 'rix', would become 'rio'. The
remainder of the title, 'thamus' without the Latin '-us' nominative
suffix is 'tham'. In the process of undergoing change from Brythonic
to early Welsh, many times a 'd' or 't' would end up as a 'dd'
(voiced as a 'th'); but this particular change could be before the
Brythonic 'm' altered to a 'v' (spelled 'f' in Welsh). This leaves
either 'tam' or 'dam'.