The English came in after the Romans left — actually before that — and that’s the reason the British civilization of the time went all to heck. But it wasn’t entirely that way, as at least two sites (one well inland) were linked by trade with the Byzantine Empire.
The Romans had no educational system, other than private tutoring (often by slaves) which led to an uneven level of literacy throughout the empire. In Ostia there’s a mostly intact restaurant from Roman times (not in operation of course; the waitresses would be pretty old, for one thing) and their popular offerings are depicted in mosaic, with no text.
Just like in a modern restaurant.