This post is just really just a little brain storming….
It is generally known that major agricultural and landscape usage changes occurred in post-Roman Britain. Former agricultural land becomes reforested and naturally, Roman water management projects eventually fail. Roman withdrawal from the island in the early fifth century is the usual explanation. Romans leave and the poor hapless Britons can’t manage without them. While there were surely major sociocultural changes going on, it never really made sense for the landscape change on such a massive scale. I expect the roads and bridges not to be kept up, defensive clearances around fortifications to be partially reforested, and large estates would have broken up. This really doesn’t explain to me the loss of agricultural land to reforestation that occurred in parts of the island that lacked dense Roman estates. Afterall, most peasants would not have been able to evacuate the land and would have turned large estates into smaller farmsteads. New local leaders would have still been interested in food stuffs even if trade routes were drastically changes. So if most people could not have evacuated, where did they go? And is this tied to the Romano-British being able to hold Anglo-Saxon advance for over a century until a fairly rapid collapse in the sixth century? Other the settlement of Brittany in the 5th-6th century, there are no known large-scale migrations of Britons to the continent to account for the abrupt collapse after over 150 years since the Roman withdrawal. The Britons held their own very well considering how fast the Franks and Goths got control of their former Roman provinces.
So now jumping to some of my reading on plague studies…. large scale land use and agricultural change occurs in Britain after the Black Death. This is a product of not just the Black Death but also a century of ecological change that resulted in livestock murrains, famines, and culminated in the Black Death. Economists like to point out all the benefits of the fall in demographics on economics and eroding the social structures that kept the masses poor and tied to the land. After the Black Death, landscape changes begin resulting from changing agricultural styles, more pasture is available and less under cultivation. There is also an abrupt stop in building because the population has shrunk to the point where new structures are not needed. A stoppage in building also makes changes in building style more pronounced when building begins again at a slower pace after a couple of decades. It could be argued that the post-Roman period is one of the few eras in British history where land change occurred as drastically as after the Black Death. Ecologically should these periods be studied together? (Are there other periods in British history with similar amounts of change?)
Has too much of the post-Roman Britain change been credited to the Anglo-Saxons? What is the role of the plague of Justinian, from 541 and returning to Ireland in a couple more ‘waves’ before 664, in creating the right demographics for political change? Yes, plague would have effected the Anglo-Saxons also but they did not have the trade networks of the western Britons and Ireland to facilitate rapid transmission. There are also other ecological changes going on that may have precipitated the plague of Justinian. Social isolation (even incomplete) is a blessing in times of plague. All food for thought. As always looking for comments and suggestions….