A skeptical read would be that the economics of Norman style feudalism heavily relies on the peasants to work the land. Obviously you need the peasants to stay in their place. If all the warrior caste have the same perspective, you can't be carting off the population and selling them off overseas, without some major friction. And if you are trying to "take" some land from another warlord, it's not going to be very economical for you to sell off the peasants, cause then who is going to work the land?
Yeah but that region wasn't as economically important. And it had a critical problem where it was the border region with Scotland and a preferred entry point for the Danes. Depopulating the area makes sense from a medieval military perspective because invaders won't have crops and infrastructure to pull from as they transverse the region. Other states in this time period had similar state-directed depopulated areas on the border for the same reasons.
What are some other examples? That's such a fascinating practice. Was it done in the ancient world as well? What about in other places (Asia, Americas)?
Off the top of my head, China’s Great Clearance [1] and the Desert of the Duero in Spain [2]. IIRC the area north of Hadrian’s wall was also kept depopulated.
The Habsburg Military Frontier [3] could probably qualify too but the area was somewhat populated by soldier-settlers.
It was pretty common practice from ancient through to modern times for a resisting or rebellious population (especially a city) to be slaughtered or enslaved. A few examples would be the Roman massacres in Judea, the destruction of Baghdad by the Mongols or the wars against Native Americans.
Right, but I was specifically asking about the practice of slaughtering/enslaving or otherwise depopulating an area specifically for the purpose of creating an economically/politically undesirable buffer zone against invaders.
It was pretty common practice .. by some extremely aggressive groups .. from ancient through to modern times .. by war-like nations. Yes Romans.. not everyone did this worldwide. The world has been wounded repeatedly by the extreme brutality of some armed groups. It is simply false to ascribe this behavior to "pretty common" without distinction, and IMO makes the horrible into some kind of banality.
I would argue that the groups you label extremely aggressive were just the winners, and the other “less brutal” groups would have done the same thing if the boot was on the other foot.
Other folks may have more apt examples to share, but I would examine the history of Dacia and also the Sasanian fortification lines both east and west (but especially east) of the Caspian Sea -- both of which separated the empire from nomadic tribes of the steppe.
I believe these involved depopulated regions both north and south of the main defensive structures to allow harrying of invading forces while denying access to plundered resources.
Eventually, they were overcome by the Hephthalites (aka White Huns) following heavy Sasanian losses north of the limes in the AD 484 Battle of Herat, but it's interesting to note that the defensive structures separating southern 'civilization' from the steppe were considered a joint responsibility of the predominant (Roman/Sasanian) empires in spite of their generally being at war with each other, as the nomads were a shared threat.
Edit: Another great example is drawn from Caesar's description of Helvetian practices in his Gallic Wars; the Helvetians, a Germanic tribe located in modern Switzerland, had deliberately depopulated a wide area around their territory for defensive purposes.
I'd go slightly further than "pretty harsh". It was basically ethnic cleansing. Albeit an incomplete and fairly moderate one as these sorts of genocidal things go
A really thorough ethnic cleansing is generally more difficult without modern government structures and mass media to really gin up the hate: in Rwanda, ordinary Hutu slaughtered half a million Tutsi in three months -- 2/3 of the entire Tutsi population at the time -- and they did it with garden tools[1].
That kind of death used to take a standing army backed by decades, if not centuries, of training and discipline: Caesar's slaughter of the Helvetii is the first that comes to mind, maybe followed by the Qin wiping out the Song during China's Warring States period.
