The genetics of Europe are a bit strange. Just within historic times, it has seen waves of migrations, invasions, and the rise and fall of empires—all of which should have mixed its populations up thoroughly. Yet, if you look at the modern populations, there's little sign of all this upheaval and some indications that many of the populations have been in place since agriculture spread across the continent.

This was rarely more obvious than during the contraction and collapse of the Roman Empire. Various Germanic tribes from northeastern Europe poured into Roman territory in the west only to be followed by the force they were fleeing, the Huns. Before it was over, one of the groups ended up founding a kingdom in North Africa that extended throughout much of the Mediterranean, while another ended up controlling much of Italy.

It's that last group, the Longobards (often shorted as "Lombards"), that is the focus of a new paper. We know very little of them or any of the other barbarian tribes that roared through Western Europe other than roughly contemporary descriptions of where they came from. But a study of the DNA left behind in the cemeteries of the Longobards provides some indication of their origins and how they interacted with the Europeans they encountered.

Grave issues

The Longobards entered the historical record when they were northeast of Roman territory, roughly in the area of what is now Poland. They crossed what was nominally Roman territory into what was called Pannonia and, among other things, left behind a cemetery called Szólád, now within Hungary. In 568 CE, a war between the Goths and Byzantine Romans on the Italian Peninsula left both weakened. The Longobards moved in, kicked both out, and founded kingdoms that would remain in place for two hundred years. A second cemetery in this study, Collegno, dates from that era (it's near Turin, Italy).

Both cemeteries feature bodies buried with a variety of grave goods, including weapons. In both cases, one of the individuals present was buried with a horse. Carbon dating has confirmed they were in use during the time the Longobards occupied the area, and similar graves have been found throughout northern Italy dating from this period.

The big change with the new work is that the authors added genomics, isolating DNA from each of the buried skeletons and, when the quality permitted, doing a full genome sequence. Where the quality wasn't good enough, the researchers performed a simpler genotyping procedure similar to that used by commercial testing companies. In addition, more of the skeletons were subjected to analysis of isotopes that indicated what they were eating and whether they had grown up in the same area they were now living.

A family affair

The DNA evidence included a major surprise: both cemeteries included groups of family members buried together. In Hungary, there were four families with multiple members buried in the cemetery and clustered together; Italy had three families.

The genomes indicated that the families had originated in Northern Europe, consistent with the Longobards being a Germanic group (and indicating they had not recently arrived there from somewhere else). But things got complicated quickly. Even in Hungary, many of the individuals had a significant contribution from Southern Europeans in their ancestry—in one case, a female skeleton looks like it's French, in genetic terms. One of the families was largely a mix of Southern European with contributions from the Iberian Peninsula—only a few of the family members have significant Longobard contributions.

Similar things were apparent in Italy. While one family appears to be entirely from Northern Europe, the remainders are a mix, with one of them being nearly entirely Southern European and Iberian.

The isotopes also tell two different tales. In Italy, the family with a large Southern European contribution seems to have been living in the area where they were eventually buried. Other people buried there, who had more Northern European ancestry, had an isotopic signature that didn't match the location conditions, suggesting they had migrated there from elsewhere. By contrast, the Southern Europeans in the Hungarian cemetery seemed to have arrived there from elsewhere, much as the Longobards had.

The split was also notable in terms of the items buried with these families. "Individuals with predominantly central/northern and southern European ancestry possess very distinctive grave furnishings," the researchers note.

Mixing and fading

All of this paints a picture that's consistent with the spotty historical record. The Longobards arrived in the area of what is now Hungary from Northern Europe and then moved into Italy, where they remained and buried several generations of their family members. In both locations, however, there are signs of the turmoil gripping Europe at the time. Several families show indications of marrying people from outside the Longobard culture, and at least one family in each location appears to have been from Southern Europe.

This suggests a degree of cultural mixing, given that both groups appear to have buried their dead in the same location. The genetics also show a degree of ancestry mixing, as you'd expect in cases where the groups lived together for centuries.

While the study paints a picture of cultural and genetic turmoil that matches the historical record, somehow its effects ended up being transient. "We observe that central/northern European ancestry is dominant in both Szólád and Collegno," the authors note, "and that modern genetic data do not show a preponderance of such ancestry in either Hungary or northern Italy." For whatever reason, despite ruling Italy for centuries, the Longobards seem to have faded into genetic obscurity.

Nature Communications, 2017. DOI: 10.1038/s41467-018-06024-4 (About DOIs).