There are maps (mentioned in the article), and accounts of the "Saxi" (which might have meant "the Saxons"). What other evidence would you expect to show what

There are maps (mentioned in the article), and accounts of the "Saxi" (which might have meant "the Saxons"). What other evidence would you expect to show what language the inhabitants spoke? Religious text (ie, almost all writing) would have been in Latin or Greek. Coins were shared across regions.