>We know about the ruling bloodlines.
I agree with you anon except that the whole bloodline thing is not very clear as yet. It is really clear that the current Ashkanazi jews are Germans. Considering that Yiddish is directly related to Old German.
https://www.nytimes.com/1996/10/29/science/scholars-debate-roots-of-yiddish-migration-of-jews.html
My guess is that it is a merger of the Teutonic Knights and local semites during the Outremer project (crusades)