Conan Meriadoc (; ; ) is a legendary British Celtic leader credited with founding Brittany. Versions of his story circulated in both Brittany and Great Britain from at least the early 12th century, and supplanted earlier legends of Brittany's foundation. His story is known in two major versions, which appear in the Welsh text known as The Dream of Macsen Wledig, and in Geoffrey of Monmouth's Historia Regum Britanniae. Both texts associate him with Magnus Maximus (Macsen Wledic, reigned 383–388), a Roman usurper against the Valentinianic dynasty who was widely regarded as having deprived Britain of its defences when he took its legions to claim the imperial throne. Conan's cousin or sister, Saint Elen, is said to have been Macsen Wledic's wife.
Early evidence
The earliest undisputed evidence connecting Conan to the foundation of Brittany appears in the Life of Saint Gurthiern, included in the Kemperle Cartulary compiled between 1118 and 1127. This text traces the descent of Gurthiern back to the ancestor figure Beli Mawr, given as a son of Outham Senis (Outham the Old), the figure known in later sources as Eudaf Hen and Octavius. Outham is given another son, Kenan (an Old Welsh spelling of Conan), who is said to have been the founder of Brittany. This reference shows that the Conan story was known in Brittany from a comparatively early date, but certain evidence suggests that it was imported from Wales. The text's compiler, Gurheden, says that his source for the information was one "Iuthael son of Aidan"; while the name Iuthael is a brittonic name known in Wales and Brittany as well as Devon and Cornwall, the Gaelic Aidan is not attested in early Brittany but is known in Wales. Additionally, Gurthiern's genealogy corresponds strongly with the descent elsewhere attributed to the Welsh saint Cadoc, further suggesting a Welsh origin.
There is evidence that Conan Meriadoc figured into the brittonic prophetic tradition as a messianic saviour who would return to lead his people in a time of need. A Cynan appears in several prophetic poems, most notably the Armes Prydein, where he is named alongside Cadwaladr as a figure whose return is promised.
The version of the story given in The Dream of Macsen Wledig differs from the Historia account on a number of points. Though the text postdates Geoffrey, it contains material older than either version. In The Dream, Conan is the son, rather than nephew, of Eudaf Hen (Geoffrey's Octavius), and the brother of Saint Elen. Maxen Wledig (Magnus Maximus), here portrayed as the rightful Roman Emperor rather than a usurper, sees Elen and her kingdom in a dream vision, and seeks her out and marries her. In this version Conan and his brother Afaon immediately become Maxen's loyal associates, later helping him reclaim the throne of Rome. For this service the grateful Macsen gives Conan dispensation to lead his army to conquer whatever realm he wants. Conan chooses Armorica, where he kills all the men and replaces them with his own soldiers. He then orders the tongues of all the women cut out, lest their speech corrupt that of the Britons; a fanciful etymology connects this event with Welsh name of Brittany, Llydaw, supposedly from the Welsh lled-taw or "half-silent".
Later developments
The Conan story became a dominant founding myth for the Bretons for hundreds of years. Especially important in this regard are the stories of the so-called Seven Founder Saints of Brittany, which were largely forgotten or overlooked after the spread of the Conan legend.
In the wake of Geoffrey and The Dream of Macsen, Conan subsequently appears as a founder-figure in several genealogies of Breton aristocratic families. He is venerated as the ancestor of the Rohans, according to the Life of Saint Meriadoc, the protagonist of which is said to have been descended from him. Meriadoc appears in one of the genealogies from Jesus College MS 20, which traces the descent of Geraint mab Erbin, king of Dumnonia in the West Country, back to "Cynan map Eudaf Hen". The story's political impact declined with the Union of Brittany and France in 1532, and it thereafter declined in popularity. However, in the 17th century the Rohans used their supposed descent from Conan Meriadoc to seek status as "foreign princes" at the French court; King Louis XIV recognised their pedigree, but denied their foreign status.