In the 800s and 900s, Western Europe was beset by many raids by various outside peoples. This caused a lot of disorder, leading to the rise of Feudalism and Manorialism. The invasions caused a lot of disruption in Europe, and much of the progress gained in the Carolingian renaissance was lost.
One of these groups was the Vikings. The Vikings became especially overwhelming after the death of Louis the Pious, the son of Charlemagne. The Vikings sailed down from Scandinavia and attacked coastal towns, and eventually made their attacks further inland. Their attacks utterly devastated the land: They burned villages and farms, destroyed churches and monasteries, looted the places they attacked, and carried people away into slavery. The Vikings didn’t really stay in the places they conquered, they raided and then returned home. They wanted gold, silver, and jewels, which they found in many monasteries.
The kings were too weak to provide much protection for their people, so the people were pretty much on their own. In 911, Charles the Simple, the king of France, tried to appease the Vikings by giving the Vikings the land of Normandy to rule as vassals. But, the land was still technically his because he had made them vassals, not the sole rulers of Normandy.
The Vikings were not the only people that attacked the people of Western Europe. The Magyars were also a big threat to the people of Europe. The Magyars were of Asiatic origin, exactly where they were from is unknown. They attacked Germany, Northern Italy, and parts of France. They were a major threat from the late 9th century to the mid-10th century. They eventually became Christianized and formed the Christian kingdom of Hungary.
The Muslims were the third group that threatened Western Civilization during this time. They had expanded rapidly after the death of Mohammad, conquering much of the Middle east, North Africa, Spain, and other places. They plundered, kidnapped, and looted many towns and cities. The fighting eventually wound down by the late tenth century.
So what did the common people do in response to all of this? Many of the victims of these raids, especially the Viking raids, sought protection from the strong and rich people nearby. These people usually had a lot of land, but they didn’t get enough productivity from it because they didn’t have enough people to care for it. The people would exchange labor for the protection of these people, establishing Manorialism in many places in Europe. The rulers of the Manors, as they were called, were known as lords.
The lords had people to take care of the land, but sometimes they needed more people to take care of the land and defend it. To take care of this, the lord would keep some of the land as his own demesne, while the rest he gave out to his trusted followers as fiefs. These companions would be known as vassals. Ultimately, thought the lord would still own the land. This practice is known as feudalism. The fiefs would provide income for the vassals, which would provide them with leisure time to practice using weapons on a horse. Vassals would also advise the lord and exercise political authority over their fiefs. Sometimes, vassals would appoint other vassals underneath them, and would act as their lords. This practice was known as subinfeudation.