Explanation and Answer:
The Christianization of Scandinavia, which includes Norway and Sweden, took place between the 8th and the 12th centuries. The conversion of Scandinavian kings occurred over the period 960–10201. Denmark was the first Scandinavian country to Christianize, as Harald Bluetooth declared this around AD.
Although Sweden was officially Christianized by the 12th century, the Norwegian king Sigurd the Crusader undertook a crusade against Småland, the south-eastern part of the Swedish kingdom, in the early 12th century. It’s important to note that while the Scandinavians became nominally Christian, it took considerably longer for actual Christian beliefs to establish themselves among the people in some regions.
In some cases, the people were Christianized before the king. Despite these nations being collectively converted by 1100 A.D., some regions that converted later than others were the last to receive missionaries.