Even before the beginning of Christianization, the Vikings came into contact with Christianity. For centuries, they encountered the Christian world through military campaigns, service in mercenary armies, trade and diplomacy and shared their experiences with their compatriots. The infamous raids started at the end of the 8th century forced the Christian rulers to carry out an organized and systematic Christianization of the Vikings with the aim of preserving Christian and European values. After difficult beginnings, general Christianization began with the Christianization of the Viking rulers. Viking rulers consciously accepted Christianity for political and economic interests. Christianity spread from the baptized kings to the aristocracy, and then to other classes. Rulers distributed social privileges and material rewards to their subjects for accepting Christianity. In order to make the Christianization of the Viking world as successful as possible, Christian missionaries ingeniously incorporated Christian elements into pagan traditions, creating regional versions of Christianity. The process of Christianizing Scandinavia lasted for centuries, as the old gods, rituals and customs gradually disappeared, and the new Christian teaching spread throughout the Viking world. Numerous monks participated in the entire process of Christianization, the most important of whom were members of the Benedictine order. Ansgar is certainly the most important Benedictine monk, later the Archbishop of Hamburg-Bremen, who participated in the Christianization of the Viking world. Ansgar, also known as the Apostle of the North, later became the patron saint of Scandinavia. The circle of influence of Christianization and Europeanization doubled during the Viking Age, spreading through Eastern and Northern Europe, which enabled a significant increase in the number of the European population. With the increase in population, prerequisites were created for the further development of agriculture, trade, education, state organization and the army, which represents the foundations of modern Western society. The Christianization of Scandinavia, the establishment of centralized Scandinavian kingdoms, the flourishing of trade around the Baltic Sea and the rapid development of the entire Christian Europe should be viewed in mutually intertwined cause-and-effect relationships.