I've traced my family back to 8th century Wales (so far). I hope this isn't a stupid question, but where did?

I would love to see the documentation on your research, because there are no known records that go back that far and no known written language from that period. In the 8th Century, Wales was inhabited by the Celts, and the Pics. The Celts are believed to have come from Europe via a land bridge. The Pics were indigenous people and their origin is not known.