Doppleganger, Where Did That Come From?

Dopple ganger came directly from the german word doppleganger, but it went through a little english phrase first. In german folklore, we all have a spirit double who's invisible but identical to us and that exists when we're alive. Rit love your pot. Haf discovered it about five months ago, and i'm just loving it. Listend to it every night. You probably covered it already, but dople ganger, where did that ever come from? Or what's the derivation of dopple gangers?