The first person to apply the Anglo-Saxon label to Britain was a Benedictine monk named Bede, whose sweeping and long-definitive ethnography of eighth-century England was about as precise and scientific as you'd expect for the era. Bede's history declared that Britons descended from two Germanic tribes and one Dutch: the Angles, the Saxons, and the Jutes. But these migrants only started moving in after the Roman Empire's fifth century withdrawal, and anthropologists today do not seem to consider their impact as nearly so definitive as Bede did.

Anthropologists have disproven some of Bede's key claims, which long supported the idea that England is inherently Anglo-Saxon. Bede says entire German regions emptied onto the British isle, but today it looks like only perhaps 10,000 to 25,000 Angles and Saxons crossed over during the centuries of migration. These migrants settled in among the millions of people who were already there, ruling over parts of the island until the eleventh century Norman invasion.

The idea that Anglo-Saxon invaders defined or even significantly influenced British genetics has been "widely discredited," according to National Geographic, which quotes an archaeologist named David Miles. "Probably what we're dealing with is a majority of British people who were dominated politically by a new elite," Miles told the magazine. "They were swamped culturally but not genetically." It seems that Anglo-Saxons represented an elite minority, not the country in its entirety, and one that did not rule permanently.

Even their cultural influence declined with the 1066 conquest by Normandy, today a region of France. The new Norman rulers transformed England and ejected the old Anglo-Saxon elite, many of whom fled the country entirely. And so the Anglo-Saxon era ended, four or five centuries of rule that ended a thousand years ago and did not appear to make a lasting or substantial impact on British genes.

So, Anglo-Saxon is a bit of a misnomer, but even if we look past that and just accept the term as a colloquialism for the English people who were long ago ruled by Angle and Saxon lords, the idea that the U.S. and U.K. share an Anglo-Saxon identity still isn't really accurate. The 2001 U.K. census found that 85 percent of the country is ethnically "white British," which includes the Irish and Scottish whose forefathers were never under Anglo-Saxon rule.

And, though the United States began its history as an English-speaking colony of Britain, and has retained much of the English political and legal systems, it's not really an ethnic English country anymore. America's population has exploded by a factor of over 100 since declaring independence, much of that growth coming from slavery and immigration, neither of which drew heavily from England. In the 2000 U.S. census, only 8.7 percent of Americans identify their ancestry as English, which is ranked fourth behind German, Irish, and African-American.