The Arthurian cycle as it exists in modern popular imagination--Arthur and the Knights of the Round Table, the wise wizard Merlin, the quest for the Holy Grail, the love triangle of the king, his queen Guinevere, and his peerless champion Lancelot--is largely a product of literature in Northern French dialects (langues d’oïl) from the late twelfth and thirteenth centuries CE. Many other languages have significant medieval Arthurian literatures; key foundational texts are in Latin, there are important romances in Middle High and Low German and Castilian, and an especially notable canon spans early Middle to Modern English. There are Arthurian tales in Hebrew, Old Norse, literary Greek, Middle Irish, and most of the languages in between. But for sheer volume, cohesiveness, and influence, French Arthurian literature takes precedence.

However, medieval French authors were unanimous in ascribing the origins of the Arthurian legends to li bretun(s). What exactly they meant by this has been a source of some contention, but it is probably safest to understand this term as referring to broadly to speakers of Brittonic languages--—Breton/Brezhoneg, Cornish/Kernowek, and Welsh/Cymraeg (and perhaps Cumbric, depending on when it actually went extinct). By the twelfth century, these peoples were far from monolithic, politically, culturally, or linguistically. But they were not often rigorously delineated in Old French dialects, and were perceived by others--and to some extent by themselves--as possessing certain cultural commonalities. For Arthurian materials, Welsh holds pride of place, since the oldest Arthurian texts are in Welsh or Latin composed in Wales. The Welsh seem to have thought of Arthur as their own, though the old sources are coy on his exact geographical origins, with Cornwall and Yr Hen Ogledd (“The Old North,” roughly the modern Anglo-Scottish border) having claims at least as good as Wales itself. It is thoroughly plausible that Arthur was known as a folk hero or legendary figure across all these territories, and localized in different places at different times. The lack of medieval written material in Breton and Cornish complicates these questions; Cornwall likely never had much of a manuscript culture, while irreparable loss of Breton sources may have occurred in the Revolutionary era.

But how exactly the Arthurian mythos went from a set of tales native to the coastal fringe of Northwestern Europe, to an international franchise rooted in French chivalric culture, remains a bit of a mystery. One of the most prominent Arthurian scholars of the twentieth century, Roger Sherman Loomis (1887-1966) devoted much of his research to permutations of this question. Many of Loomis’s conclusions do not stand up to modern scholarly scrutiny, but the time and ink he devoted to these issues indicates their complexity, and helped set the terms of the field.

The most straightforward accounting for Arthur’s popularity outside his native turf points to the work of Geoffrey of Monmouth and Wace. You mention Wace in your question, so I assume you’re somewhat familiar with his contributions, but just to summarize: Geoffrey, a cleric from the Anglo-Welsh border, completed his Historia Regum Britanniae (“History of the Kings of Britain”) by 1139. In accessible Latin prose, he told the stories of Britain’s pre-Saxon kings from Aeneas’s great-grandson, Brutus, who wrested the islands from tribes of primordial giants, to Cadualadrus (Cadwallader), who died in the late seventh century. At the center of the book, alongside other future blockbusters like King Lear and Cymbeline, is the first written account that offers a complete life of King Arthur (Arturus), from conception to death. Elements as central to the modern canon as Arthur’s connection to a conjurer/half-demon named Merlin and his ultimate betrayal by his nephew Modred appear for the first time in the HRB. Issues with Geoffrey’s sources (or the lack thereof) have been raised since his own era, and there is undoubtedly a great deal of invention and innovation in the HRB alongside borrowings from Latin histories, chronicles, and saints’ lives; Cornish folklore; Welsh prophetic and perhaps heroic poems/sagas; classical allusions; and contemporary political resonances. These diverse influences also contributed to the polyvalent ways that Geoffrey’s work was received. It could be read as prefiguring Norman hegemony in its vision of Arthur’s continental empire, or as justifying the conquest and colonization of li bretuns since their fall from imperial grandeur; or as promoting a vision of once-and-future Brittonic greatness (certainly the Welsh seemed to understand it this way); or as presenting an essentially fantastic saga, an exercise in speculative worldbuilding that invited contributions from those with no particular cultural or political connections to the origins of the mythos.

Some two decades after Geoffrey completed his Historia, the Jersey poet Wace adapted it into a popular new literary form, the roman. Written in rollicking eight-syllable rhyming verse, the roman told an extended narrative drawn from an antique source (often Greco-Roman antiquity, at least at first) and usually contained both fight scenes and love stories. Wace’s Roman de Brut hews fairly close to the Historia, at least by the standards of medieval translation/adaptation, but it does add some important material--most famously, the notion of the Round Table. Wace also alludes to a period between Arthur’s wars when his knights became concerned with individual adventures and love affairs. This “gap” became the site of many subsequent insertions and additions to the legend, until by the time of Malory’s Morte d’Arthur (1485), the foreign wars that occupy much of the HRB/RdB’s Arthurian narrative have shrunk to brief passages, and the quests of individual knights take up the vast majority of the text.

Wace’s work was completed right around the time Henry II ascended to the English throne. Over the course of his reign, Henry would assemble a fractious polity encompassing much of modern western France, England, southern Wales, and eastern Ireland, the so-called “Angevin Empire” that you mention in your question (which not coincidentally included many of the areas inhabited by li bretuns). The Anglo-Norman nobility maintained close ties with relatives, allies, and rivals throughout Europe, including in southern Italy, Sicily, and the Crusader States of the Outremer. These far-flung courtly networks provide a clear context for the dissemination, popularization, and cross-pollination of Arthurian literature. The great French Arthurian writers of the second half of the 12th century--Marie de France, Chrétien de Troyes, Robert de Boron, Thomas de Bretagne--can all be fit into this scheme, though biographical information is scanty even for Chrétien and essentially nonexistent for Marie, Robert, and Thomas.

However, this straightforward narrative leaves much unexplained. One of Loomis’s favorite pieces of evidence was a dramatic semicircular carving that arcs above the Porta della Pescheria (Fishmarket Gate) of Modena Cathedral. You can see it here: six mounted warriors ride against a three-turreted structure defended by a dismounted man with a pickaxe and another mounted warrior. The central keep, surrounded by water, is flanked by a woman and another unarmed man. Helpfully, each figure is labelled: the attackers include Isdernvs, Artvs de Bretania (“Artus of Britain”), Galvagin, Galvarivn, and Che; the pickaxe-wielder is Bvrmaltvs, the knightly defender is Carrado; the woman in the fort is Winlogee, while the man with her is Mardoc. It is a striking piece, carved in monumental stone a thousand miles south of the Arthurian heartland, and contemporary with the earliest Arthurian literature outside the Brittonic world, or even predating it by a few decades. While Loomis’s specific reading of the Modena archivolt is untenable, his fundamental question--how did this come to be?--remains challenging to answer.

(cont.)