Sut mae?  Sut rydych chi?”

I’m going to assume that most readers did not understand those phrases, which translate roughly to “How are you?  How are things going?”  And that lack of comprehension is a critical historical fact, because, if a generation of British historians and archaeologists is correct, then you should have no problem in following that conversation.  The words are in Welsh, which is the lineal descendant of the Celtic languages that ordinary people spoke in Britain for many centuries before about a.d. 400.  Yet somehow, between 400 and 600, that older language more or less disappeared in the most prosperous parts of that island, which became England.  It was English, not British or Welsh, that spread around the world.

How did the linguistic change happen?  Up till 60 years ago, the answer was simple.  At the end of the Roman Empire, Britain was raided by Germanic peoples, variously known as Angles, Saxons, Frisians, and Jutes.  Hoping to buy them off, British rulers took some of those barbarians into their service, but around 440, the mercenaries rebelled and launched a horrendous massacre described by the British writer Gildas.  Native British peoples were annihilated or ethnically cleansed, or else survived as slaves and tributary peoples on the distant margins of society.  By the seventh century Germanic peoples had spread their rule over what became the land of the Angles, England.

In recent decades, that once-familiar narrative has become almost laughably unfashionable.  At every stage, the story offends the sensibilities of liberal or leftist scholars, who are appalled at the idea of war and invasion being responsible for mighty social changes.  And speaking of civilization or Dark Ages implied that we could somehow evaluate or judge different societies, placing some higher or lower in the scale.  Do these concepts not justify racism, imperialism, and militarism?  The image of high civilization under barbarian assault had alarming implications for modern debates over immigration and multiculturalism.

From the 1960’s, then, archeologists stressed instead the continuities uniting the older Britain with the new England.  They underplayed the “civilized” nature of the fading society, stressing that Roman culture remained only a veneer overlaying a largely peasant native society.  Anglo-Saxon peoples then arrived in Britain as invited guests, whose tastes and styles gradually spread through the whole community.  As the cities and villas crumbled, so the two races merged quite peacefully.  By the time Anglo-Saxon England emerges in the historical record in the eighth century, it has thoroughly united its Celtic and Germanic roots in a triumph of multicultural integration.

But what do we do with that thorny linguistic issue?  Because in England at least—as opposed to Wales and Scotland—the Celtic languages simply did not survive, with the trivial exception of a couple of dialect words (crag for rock, brock for badger).  This was a process utterly different from what happened on the Continent, where the descendants of the Germanic peoples all adopted the Latin languages, which evolved into French, Spanish, and the other Romance tongues.  The British language, however, enjoyed no such afterlife, and a common-sense approach surely suggests that its speakers themselves vanished.

Not a bit of it, proclaim recent historians.  Languages, in this view, are fashion items, like styles in hair and jewelry, and are adopted through a comparable process of diffusion.  As Anglo-Saxon styles became popular, the British took up the new language as the fashionable thing to do.  Presumably bands of star-struck Celts followed a Saxon chief, calling, “Prithee, my Lord!  Canst thou help us with our strong verbs?”

Those arguments could have gone on indefinitely, except that incontestable new evidence tells us exactly what did happen at the end of Roman Britain.  The new data come from genetics, and particularly from recent studies coordinated by Harvard medievalist Michael McCormick.  If we trace the Y chromosomes passed down through males, we find overwhelmingly strong genetic links between the male inheritance of the English and that of Frisia, the reported home of many of the invaders.  In contrast, genetic ties between the Germanic English and the Celtic Welsh are very slim indeed.  We can now say confidently that when the Germanic peoples entered Britain, they interbred enthusiastically with native women, but that native male lines effectively vanished.  Possibly the invaders systematically killed all males they encountered, or else surviving Celtic men were so enslaved and humiliated that they had little chance of passing on their genes.  But in either scenario, a million Romano-British men alive in 400 vanished without genetic trace.  Gildas, in other words, was portraying sober, gruesome, fact.

Historians invent comfortable fictions to justify their political ideologies, but eventually the myths fracture, leaving us to confront unpleasant facts about the fate of civilized societies that fail to defend themselves.  Sometimes the barbarians are real, and they do act like barbarians.