Situated at the margin of Europe, Sweden was not much affected by the great migrations or the Christian missions during the 5^th and 8^th centuries. Only from the 9^th century onwards, a sustained endeavour to include Sweden in Christian Europe is discernible, ending in the creation of the ecclesiastic province of Uppsala in 1164, comprising the Swedish kingdom. The Christianization of Sweden was brought about without exterior military pressure or visible interior unrest. An interdisciplinary research group has been formed to study the Christianization of Sweden, and the paper is largely based on publications of this group. Two fields of discussion, where different approaches meet, have been chosen for the discussion. One is the debate considering the relative importance of phenomena of continuity and rupture respectively in the process of Christianization, e.g. concerning cult places, religious customs and burial. The other is the discussion of how the missions were organized and carried out, e.g. the relative importance of English, German and Roman influence on the establishing of Christian institutions in Sweden.