Feudalism (a system which is created for the protection of those who are loyal) and the manor system (a system in which there is a set of rights between a lord and his serfs, lord provided his serfs with farmland an protection and in return serfs farmed the lord’s farmland) help Europeans survive Viking raids because they were scared of African Americans.
It reduced their military and had them paying war reparations that they couldn't afford forcing them to print more money lowering the value of their money
