England
Consequences of the Wars
The Wars of the Roses were a true civil war, for they involved more than a simple competition between rival claimants to the throne. Equally as important were rivalries between familes such as the Nevilles and the Percies for control of Northumbria. As the Wars progressed, these rivalries were exacerbated rather than ameliorated, until one side or the other was simply destroyed (though a few did manage to make it through).
Unlike the Hundred Years' War, the Wars of the Roses did not lead to any profound socio-economic changes. Rather, they were a reflection of changes. Specifically, the Wars are a sterling and bloody example of how little control a medieval monarch exercised over his great barons, and showed too how much public order still depended on families. For most of the armies that fought at St Albans and Towton and Barnet and Tewkesbury were private armies: raised, commanded, and financed by those same great barons whose rivalries were the source of the conflict in the first place. In the field, the kind was merely one more baron, and a singularly vulnerable one at that.
This is why we see so many examples of turncoats and betrayal. It's not that these men were disloyal as that they were loyal to other things besides the crown. The first business of a Courtenay or a Neville or a Tudor was to see to the interests of his family. If that meant supporting York, then fine, but if that meant supporting Lancaster that was fine, too. Only a few men stuck with the one side or the other even though it meant the loss of estates and titles.