Scythian descendants of Gomer, son of Japheth, son of Noah.
The word "Ashkenaz" itself first appears in the genealogy in the Tanakh (Genesis 10) as a son of Gomer and grandson of Japheth. It is thought that the name originally applied to the Scythians (Ishkuz), who were called Ashkuza in Assyrian inscriptions, and lake Ascanius and the region Ascania in Anatolia derive their names from this group. The "Ashkuza" have also been linked to the Oghuz branch of Turks including nearly all Turkic peoples today from Turkey to Turkmenistan.
Ashkenaz in later Hebrew tradition became identified with the peoples of Germany, and in particular to the area along the Rhine where the Allemani tribe once lived.
The link between Japheth and the Europeans stems from Genesis 10:5, which states that the sons of Japheth moved to the "isles of the gentiles," commonly believed to be the Greek isles.
In the Bible, Japheth is ascribed seven sons: Gomer, Magog, Tiras, Javan, Meshech, Tubal, and Madai.
In Josephus's Antiquities of the Jews, I.VI.122 (Whiston). Josephus wrote:
"Japhet, the son of Noah, had seven sons: they inhabited so, that, beginning at the mountains Taurus and Amanus, they proceeded along Asia, as far as the river Tanais (Don), and along Europe to Cadiz; and settling themselves on the lands which they light upon, which none had inhabited before, they called the nations by their own names." Josephus subsequently detailed the nations supposed to have descended from the seven sons of Japheth. Among the nations various later writers have attempted to assign to them are as follows: