Historical counterpart to the Sidhe people?
I'm writing an urban fantasy (yes, so many of them these days!) but looking up the Sidhe - both the mounds and the supposed people of the mounds - I ran across some information that implied the Sidhe may have been either Iberian or Anglo-Saxon in origin. I am wondering if there is any more information on this?
I've tried Wikipedia and Google terms "sidhe", "pre-Celtic civilizations", "pre-Roman Iberian civilizations", "Tuatha De Danaan".
Edit: Ah yes, colonial vestiges and debunked theories! Thanks for your help, everyone - I had just heard the theory mentioned, but had no idea what the reaction was to it, if there was any credence, etc. Thanks again!