Bede, Geoffrey: Cassibellaunus
Welsh: Caswallawn

British chieftain, probably of the Catuvellauni.

Cassivellaunus is first mentioned in Julius Caesar's De Bello Gallico v.11, where he is said to be the commander of the British resistance. His tribe is not named, but its location is, namely north of the Thames, apparently on its banks; this is known from other sources as the land of the Catuvellauni tribe, so it is reasonable to assume that is Cassivellaunus' tribe, though they are not mentioned. However, he may have instead been from the Cassi tribe, and his name may be a corruption of Vellaunus of the Cassi. Later, the Catuvellauni may have taken shape, their name meaning something like "Warriors of Vellaunus", catu- being a warband, related to the modern Welsh word cad "battle."

Rhys notes that Cassi could have been written Caθθi, the "s" being lisped, and thus latter Catti in Latin. There have been coins with the name Catti found near Monmouth. And so the Cassi could have become the Catti, and later the Catuvellauni after their chieftain Vellaunus, who drove off the Romans.

The name Vellaunus appears as the name of a god; one inscription is in Hières, Isère, France, where he is equated with Mercury, and the second at Caer Went, where he is equated with Mars Ocelus. It was not unusual, at any rate, for a person to take a theonym as a personal name.

Cassivellaunus in Caesar
Cassivellaunus favored guerrilla warfare; the Britons typically hid in the forests, waiting to ambush the Romans (Caesar, v.15). He also apparently sabotaged the Thames, placing wooden spikes in the riverbed, making it difficult for the Romans to advance. However, the Romans did proceed, and set the Britons to flight.

According to Caesar, Cassivellaunus was often engaged in conflict with neighboring chieftains; in particular, we're told of how he usurped the kingship of the Trinobantes, forcing Mandubracius into exile.1. Mandubracius fled to Caesar's camp, and by gaining the protection of the Romans against Cassivellaunus, five other tribes allied themselves with Caesar: the Cenimagni, the Segontiaci, the Ancalites, the Bibroci, and the Cassi. Their ambassadors alerted the Romans to where Cassivellaunus and his forces were hidden, apparently somewhere near Kent. The Romans attacked and forced Cassivellaunus' surrendur, mediated by one Commius of the Atrebati. Cassivellaunus was not then deposed or taken prisoner, but was simply warned by Caesar not to make any more mischief amongs the Britons. This was due to Caesar's retreat to Gaul, where the rebellion was still advancing, and thus Caesar was unable to hold Britain for Rome.

Cassivellaunus in Bede
Bede follows Caesar, though he spends more time on the spikes in the Thames; apparently they were still visible in his time, and were encased in lead. He also mentions the Britons' style of guerilla warfare. He also tells of Mandubracius, here called Androgeus, and the intervention of Caesar; Bede refers to the city of Trinovantum, which is apparently Geoffrey's source for his "New Troy".

Cassivellaunus in Geoffery of Monmouth
Cassivellaunus--called Cassibellaunus, as in Bede--is the son of Heli and brother to Lud and Nennius. When Lud dies, he acts as fosterfather and regent to Lud's sons Androgeus and Tenvantius, who are too young to rule. Androgeus is made duke of Trinovantum, and Tenvantius duke of Cornwall.

Caesar writes to Cassibellaunus, demanding tribute, but is refused on the Britons' common Trojan heritage with the Romans. Caesar invades, killing Nennius, but is driven back to Gaul. Two years later, Caesar attempts to invade with a larger force, and is repelled by the planting of spikes in the Thames, and is turned back again. Meanwhile, Androgeus's nephew accidently kills Cassibellaunus' nephew, and the king demands him handed over. Angry, Androgeus refuses, Cassibellaunus threatens war, and Androgeus asks Caesar for help. Caesar invades at Richborough, and Cassibellaunus is cornered, and Androgeus appeals to Caesar for a truce. Cassibellaunus is allowed to keep the kingdom, and Caesar and Androgeus return to Rome. Cassibellaunus dies, and the kingdom passes to Tenvantius.

Cassivellaunus in Welsh literature
In later Welsh literature, Cassivellaunus appears as Caswallawn, son of Beli Mawr. As in Geoffrey, his brothers are Lludd (Lud) and Nynniaw (Nennius). His sister, however, is Penardun, who married Llyr, and produced Bran, Branwen, and Manawyddan. Caswallawn usurps the kingdom of Britain from Manawyddan fab Llyr, his nephew, taking advantage of Bran's war and the death of in Ireland. He kills the seven stewards of Bran while wearing a cloak of invisibility, and causes Caradoc to die. After the Seven Survivors' eighty years of wandering, they return and do homage to Caswallawn at Oxford2.

Later, in "The Dream of Maxen", it is said that Beli's sons--and thus Caswallawn--lost the island to the Romans, specifically Maxen and the sons of Eudaf Hen; however, Maxen retreats again to the continent. This also echoes the story of Caesar's invasion of Britain, and subsequent leaving.

Some lesser-known traditions are found in the triads. Triad 51 and 95 mention the stories of Androgeus (here called Afarwy) and Caradoc's death. Triad 51 also says that Caswallawn's sister is Arianrhod, and her sons are Gwennwynwyn and Gwanar, and they went in pursuit of Caesar, going as far as Gascony. His horse is named Meinlas in another triad, and it's implied that Caesar was able to gain a foothold in Britain in exchange for the horse. Another triad names him one of the Three Golden Shoemakers, and briefly tells that he disguised himself as a shoemaker in order to find a woman named Fflur in Rome--this tradition is also refered to in a poem by Cynddelw.

It would seem that there were native traditions known by the Welsh with regards to Cassivellaunus, and they did not rely only on Caesar or Bede for their knowledge.

1. According to John Koch, this likely forms the basis of the third branch of the Mabinogi.

2. Which may refer to an event during the reign of Henry II.

Bede. The Ecclesiastical History of the English People. ed. Judith McClure, Roger Collins. NY: Oxford Universitiy Press, 1999.

Bromwich, Rachel. Trioedd Ynys Prydein. Cardiff: University of Wales Press, 2006.

Caesar, Julius. De Bello Gallico. trans. H. J. Edwards. Loeb Classical Library. Harvard: 1917.

Geoffrey of Monmouth. The History of the Kings of Britain. trans. Lewis Thorpe. NY: Penguin, 1966.

Koch, John. "A Window into the Welsh Iron Age: Manawydian, Mandubracios". Cambridge Medieval Celtic Studies 14 pp 17-52. (1987)

Rhys, John. Celtic Britain. pp. 25-31.

Back to "C" | Back to JCE

Mary Jones © 2007