They were only "dark" in Britain on the basis that the written record of the Roman scribes ceased. Life in the country did not descend into primeval chaos merely because it wasn't being written down. We now know from archaeological evidence that Celtic and Saxon Britain was anything but dark. And all done without heavy lifting gear. The Romans had pulleys and a fat lot of good it did them. So think on before you install your next obelisk.
Thing with Britain is everyone assumes we were just barbarians before the Romans arrived, but it's not true at all. We had a perfectly good language before Latin arrived, a law system, roads, and contrary to popular belief, we were civilised. There must have been something about Britain, Caesar twice tried to invade - in 54BC and 55BC - and twice driven back, before the Romans finally succeeding a century later. Mind you, we still haven't perfected underfloor heating...
