Today, around 3000 years ago, in the period of the Shoftim, the first Jewish civil war broke out in Eretz Yisrael, which led to the first Jewish settlers on the European continent.
This war was a result of the infamous story of Pilegesh BeGiv’ah, where a Jewish maiden was abused by Shevet Binyamin.
The eleven other tribes demanded that Shevet Binyamin release the perpetrators for punishment, but they refused. This resulted in a war between the eleven tribes against the tribe of Binyamin, in which they lost, and were excommunicated.
According to some commentators, 1000 members from this tribe abandoned their homeland and settled in Europe. Some claim the settled in Romania, and some claim that they settled in Ashkenaz, Germany.
Source: Esther Rabba 7:11,
Radak Shoftim 20:15;
Abarbanel & Rashi [in a note, in some editions] Shoftim 20:48