Given the interest in the Khazar theory of Ashkenazi origins, an article in today’s New York Times is of interest. The population genetic and cultural evidence has never supported this theory, but the new research adds to the verdict.
The study, published on Wednesday in the journal Cell, compared DNA extracted from the teeth of 33 men, women and children buried in the cemetery with DNA taken from hundreds of modern Jews from around the world. Previous studies have shown that modern communities are a genetic mélange, with Ashkenazim the world over carrying essentially the same collection of DNA sequences.
But the medieval remains tell a different story. They show that European Jews at the time came from two divergent gene pools.
Each group shared the same genetic ancestry, dating back to a small founder population that most likely emigrated from Southern Europe and reached the German Rhineland at the turn of the first millennium. But the DNA analysis also revealed a genetic divide among the skeletons, which could have several explanations. In one scenario, both groups originated from the Rhineland. One branch then stuck around the region, while the other headed east to modern-day Poland, Czech Republic, Austria and eastern Germany.
Alternatively, Eastern Europe might have been settled by a different population of Jews who then mixed to a limited extent with their Jewish neighbors to the west.
Either way, the two groups remained fairly isolated from each other for generations, as evidenced by their discrete genetic lineages.
Thus population genetic studies on Ashkenazim show genetic commonality “the world over,” and this study finds that the two different lineages nevertheless “shared the same genetic ancestry” prior to splitting off and then reuniting. Note that the second alternative mentioned essentially states that the two populations that later reunited started out as a single ancestral group of Jews.
The article also highlights a reality of medieval life — that towns and other jurisdictions often invited Jews in the hopes of getting some of the money they generated, essentially a way to exploit their own people.
The existence of an east-meets-west community in Erfurt is also supported by the historical record, which includes detailed accounts of a violent pogrom on March 21, 1349 — a Saturday. Angry mobs entered the local synagogue and attacked Jews in the midst of prayer. Few, if any, survived.
After the massacre, Erfurt’s leaders took possession of property and belongings. They even collected on debts owed to the murdered Jews. But just five years later, the need for lost tax revenue prompted the city to invite Jews back.
They came from far and wide. Tax records show names denoting origins from all over Europe — including some from distant cities that had experienced their own antisemitic upheavals. “In the middle of the German-speaking lands, this was the place to be at the time,” said Maria Stürzebecher, a medievalist who is the curator of the Old Synagogue Museum in Erfurt. At least, that is, until 1453, when Jews were forced out again.
And, although the new arrivals became one group, they preferentially went into business with Jews from the same area they came from, showing that genetic distance is important even in within-Jewish contexts, likely because it promotes trust, as discussed in Ch. 6 of A People That Shall Dwell Alone.
Preserved documents on money-lending practices show that the Jews from each subgroup largely formed business alliances with members of their own kind, according to Maike Lämmerhirt, a historian at the University of Erfurt and a co-author of the study. But both groups prayed in the same synagogue. They all cleansed in the same ritual bath. And, ultimately, they all lay side by side in the same cemetery.
And over the centuries, they intermarried.