The first-ever study of DNA recovered from an ancient Philistine site is providing a unique genetic insight into the origins of some of the most notorious troublemakers of the Old Testament.

The authors of the Hebrew Bible made it clear that the Philistines were not like them: This "uncircumcised" group is described in several passages as coming from the "Land of Caphtor" (modern-day Crete) before taking control of the coastal region of what is now southern Israel and the Gaza Strip. They warred with their Israelite neighbors, even seizing the Ark of the Covenant for a time. Their representatives in the Bible include the giant Goliath, who was felled by the future king David, and Delilah, who robbed the Israelite Samson of his strength by cutting his hair.

Modern archaeologists agree that the Philistines were different from their neighbors: Their arrival on the eastern shores of the Mediterranean in the early 12th century B.C. is marked by pottery with close parallels to the ancient Greek world, the use of an Aegean—instead of a Semitic—script, and the consumption of pork.

View Images DNA recovered from 10th-to-9th-century B.C. burials at the Ashkelon cemetery was compared to earlier Philistine infant burials, as well as those of individuals who lived in the area before the Philistines arrived at the beginning of the 12th century B.C. Photograph by Melissa Aja, Leon Levy Expedition

Many researchers also tie the presence of the Philistines to the exploits of the Sea Peoples, a mysterious confederation of tribes that, according to Egyptian and other historical sources, appears to have wreaked havoc across the eastern Mediterranean at the end of the Late Bronze Age in the 13th century and early 12th century B.C.

Now, a study published today in the journal Science Advances, prompted by the unprecedented 2016 discovery of a cemetery at the ancient Philistine city of Ashkelon on the southern coast of Israel, provides an intriguing look into the genetic origins and legacy of the Philistines. The research appears to support their foreign origin, but reveals that the reviled outsiders were soon marrying into the local populations.

The study analyzed DNA from ten sets of human remains recovered from Ashkelon across three different time periods: a Middle/Late Bronze Age burial ground (about 1650-1200 B.C.), which pre-dates the Philistine presence in the area; infant burials from the late 1100s B.C., following the arrival of the Philistines in the early Iron Age; and individuals buried in the Philistine cemetery in the later Iron Age (10th and ninth centuries B.C.)

The four early Iron Age DNA samples, all from infants buried beneath the floors of Philistine houses, include proportionally more “additional European ancestry” in their genetic signatures (roughly 14%) than in the pre-Philistine Bronze Age samples (2% to 9%), according to the researchers. While the origins of this additional “European ancestry” are not conclusive, the most plausible models point to Greece, Crete, Sardinia, and the Iberian peninsula.

Daniel Master, director of the Leon Levy Expedition to Ashkelon and a co-author of the study, hails the results as “direct evidence” that supports the theory that the Philistines began as migrants from the west who settled in Ashkelon in the 12th century B.C.

“It fits with the Egyptian and other texts that we have, and it fits with the [archaeological material]."

What researchers find even more unusual is that this specific “European blip” disappears quickly and is statistically insignificant in the DNA from study samples recovered from the cemetery at Ashkelon only a few centuries after the infant burials. The later Philistine burials have genetic signatures very similar to local populations who lived in the region before the Philistines showed up.

“We managed to catch this movement of people coming to Ashkelon from southern Europe,” says Michal Feldman, an archaeogeneticist at the Max Planck Institute and study co-author. “Then it disappears very quickly within 200 years, probably because [the Philistines] intermarried and this kind of genetic signature was diluted within the local population.”

“For more than a century, we have debated the question of where the Philistines came from,” writes archaeologist Eric Cline in an email from his excavation at the Canaanite site of Tel Kabri (Cline was not involved in the current research.) “Now we have the answer: Southern Europe, and probably more specifically mainland Greece, Crete, or Sardinia. This fits with what had seemed the most likely answer previously, especially judging from [the archaeological remains], and so this seems a logical finding."

Aren Maeir, an archaeologist who directs excavations at the Philistine city of Tell-es-Safi/Gath and who was also not involved in the current research, warns against oversimplifying the story of the Philistines, however, calling the Biblical villians “an ‘entagled’ or ‘transcultural’ group, consisting of peoples of various origins.”

“[W]hile I fully agree that there was a significant [foreign] component among the Philistines in the early Iron Age, these foreign components were not of one origin, and, no less important, they mixed with local Levantine populations from the early Iron Age onwards,” Maeir writes in an email.

For Master, what’s most interesting is the fact that—despite the quick genetic assimilation that the Philistines underwent —they remained a distinct cultural group that was clearly identifiable from their neighbors for more than five centuries, until they were conquered by the Babylonians in 604 B.C.