The Reformation in Sweden and Finland has often been described as a peaceful transition from a universal, albeit corrupt, Catholic church to a pure, princely-led national church, but this idealistic picture is not entirely credible. In fact, the evangelical movement made a curiously hesitant beginning in the first generation of reformers. The preconditions for the reception of Protestantism within, as well as without, Germany differed significantly, because of the pluriformity of the religious, political, social and educational landscape. However, although the shape and progress of the individual evangelical movements in the various countries were moulded by local circumstances and pressures, the early Reformation never degenerated into parochialism. For all the regional and national variations, the national/territorial Reformations remained part of the same movement.

Christianity had been brought to Sweden gradually. When Ansgar, the monk sent to the north by the emperor in 829, became archbishop of Hamburg-Bremen, he became the religious leader of the whole Nordic missionary area. Three centuries later, in the first document relating to the church and Finland, a letter from Pope Alexander III sent in 1171 to the Swedish leaders, the state of Christianity in Finland is described as precarious. The federal relationship which is reported to have existed between Sweden and Finland at this time made it possible for missionaries to promote Christianity in Finland.