What mark did the Normans leave in European culture?

What mark did the Normans leave in European culture? What were the reasons for the establishment of feudal fragmentation in Western Europe?

In European culture and history, the Normans left their mark as fierce northern warriors who plundered coastal cities for rich booty. The main attributes of the Normans can be called their drakars, harsh life, faith in the Scandinavian gods, as well as their martial art. We can say that war was an integral part of the life of the Normans. It was believed that only a warrior who died in battle could get into Valhalla. If the warrior died of old age or for other reasons, then he naturally did not get to the Valkyries feast, which was considered shameful.

The reason for the feudal fragmentation was the wars between the heirs.