Jews (tribe of Judah) are Israelites, but not all Israelites are jews. God's promise to Abraham passed from Abraham to Isaac to Jacob/Israel, who passed it to his 12 sons/grandsons. In the last chapter of Genesis, Israel outlines what will happen to each tribe (spoiler: jews don't win in the end).
Later on the tribes formed a kingdom under David, whose descendants civil war'd, breaking off between north and south. The southern part was called Judaea, while the northern part was called Israel, or, by its neighbors, "Khomri/Omri", after the ruling house:
https://en.m.wikipedia.org/wiki/OmridesThe Omrides were dispersed by the Assyrians and became known as the Κιμμεροι/Kimmeroi to the Greeks. We know them as the Cimmerians:
https://en.m.wikipedia.org/wiki/CimmeriansThe Cimmerians were chased out of the Pontic Steppe by the Scythians; they journeyed into western Europe and were known to the Romans as the Cimbri and the Sicambri, among other Gaulish tribal names.
https://en.m.wikipedia.org/wiki/CimbriFrom Scandinavia, the Cimbri ventured to Wales, where they still call their land "Cymru".
https://en.m.wikipedia.org/wiki/CymruThe Welsh were among the first nations evangelized, after Aristobulus (Romans 16:10,
https://en.m.wikipedia.org/wiki/Aristobulus_of_Britannia) evangelized them.
Remember, Christ said "I am not sent but unto the lost sheep of the House of Israel."
