What If?

[Thiudareiks Flavius]

However, the figure you use to underline that - " tiny handful of watermills in Roman Britain in around 300 AD to well over 6000 of them in England alone in 1100", rather oversimplifies thing.

I mean, of course the Roman watermills were mostly big affairs (those that we know of), state-owned or not. But one has to take into account that all of these vanished, before the number went up again to reach those 600 by the year 1100. So how many watermills in 1000 AD? In 700? 500?

They almost certainly did vanish in England with the collapse of the Roman state, so the numbers in 500 AD were likely minimal or even none. But, working from less complete surveys than the Domesday Book (which the basis for the figure of 6000 mills in 1100 AD) and from charters and archaeology, scholars like Richard Hold in The Mills of Medieval England and Terry S. Reynolds in Stronger than a Hundred Men: A History of the Vertical Waterwheel show that watermills appeared again in England as early as 640 AD and their numbers increased steadily from that point onwards.

Obviously those 6000 watermills didn't spring up suddenly out of nowhere, and the evidence shows that this large number of mills was the result of a steady and then quite rapid growth in the use of this technology in the period between 600 and 1100 AD. And similar evidence from various places in Europe indicates that this growth in the use of this technollogy in the 'Dark Ages' was not confined to England - it was Europe-wide.

Therefore I'd like to characterise the so-called dark Ages not so much for the loss of technology, but far a failure to implement it on a larger scale?

In the case of a coin economy, mass produced goods and even large-scale stone buildings that's generally true. In the case of watermills, however, it is not supported by the evidence at all. What the evidence actually shows is that the collapse of the Empire and the subsequent economic and social consequences actually stimulated the use of that technology and some others.