Public fascination with the Vikings runs high these days, with several current television series available for bloody binge-watching. But the Vikings have never really gone out of fashion, whether as pure entertainment or because of their real historical importance.

Periodically, scholars remind the public that the people we call Vikings did not think of themselves as a group and were largely, but not universally, from the geographic area we now call Scandinavia. The Viking Age, from roughly 750 to 1050, included brutal raids, extensive trading and commerce and probably a majority of people who stayed home on the farm.

Now, one of the most sweeping genetic surveys of ancient DNA ever done has broadly reinforced the current historical and archaeological understanding of the Vikings, but also offers some surprises about their travels and uncovers some poignant personal stories. Ninety researchers, led by Eske Willerslev, an ancient DNA specialist from the University of Copenhagen, reported Wednesday in the journal Nature on their analysis of the genomes of 443 ancient humans from Europe and Greenland.

Based on DNA analysis and comparison to modern populations, they found that people genetically similar to modern Danes and Norwegians generally headed West in their raids and trading, while “Swedish-like” people mostly headed East. The findings are based on graves of raiders or traders in England, Ireland, Estonia and elsewhere.

However, they found that this was only a general pattern. Sometimes Swedish-like groups headed West, and the others headed East.

They also found considerable genetic variety in the ancient remains, indicating migration of Southern Europeans, before the Viking Age, to the area of Denmark, which undermines any idea of a single Nordic genetic identity. Some of the earliest inhabitants of Britain, the Picts, were buried as Vikings, for example.

The researchers also found people of mixed Sami and European ancestry. The Sami are reindeer herders with some Asian genetic background who have lived throughout Scandinavia and in other countries for thousands of years. They have been thought to be in conflict with the Scandinavians of European heritage during the Viking age.

Dr. Willerslev said the common view was that the two groups were hostile. But perhaps, he said, there were nonhostile interactions between them leading to offspring that were of mixed heritage and part of Viking groups.

David Reich of Harvard University, a specialist in population studies based on ancient DNA who was not involved in the research, said that the survey was one of the largest ever undertaken of ancient DNA. One result of that, he said, was that not only broad patterns emerged, but also specific findings that show the relationships between people. “You get to ask detailed questions about how people are related to each other within a site,” he said.

For instance, the earliest evidence of a Viking expedition comes from a burial site dated to around 750 in Salme, Estonia, where two Viking ships were buried; seven men in one, 34 in another, with weapons, provisions, dogs and birds of prey. No one knows whether this was a raid, or a diplomatic or trading expedition gone wrong, but the men appear to have been killed violently and buried as warriors.

The DNA analysis showed that four of the men were brothers and they were related to a fifth man, perhaps an uncle. One of the report’s authors, Neil Price, an archaeologist at Uppsala University in Sweden and the author of the just published “Children of Ash And Elm: A History of the Vikings,” said: “We kind of suspected that you go raiding with your family, but it shows that they really did.”

“There’s a story behind that,” he said, “‘Saving Private Ryan’ or something.”

Soon to be available for binge-watching on your favorite Viking channel.