I can answer your question regarding Norway specifically. Sadly, I do not have the knowledge to answer about the rest of Scandinavia, but from what I have about Norway there will be both crusades and investiture crisis, as well as some conflicts regarding the power of church law and national law. I will also just limit this answer to events happening before the bubonic plague because that is what I know the best.

Before I begin I will just make you aware that I use the word church in two ways. The first is the religious building and the other is about the religious institutions. In some of the paragraphs the word is used quite a lot and often I am changing which of the meanings I refer to, although I have tried to make it as clear as possible which one I am talking about when.

So, let us begin in the beginning. Christianity was introduced into Norway as a continual process during the 10th and 11th centuries. Multiple Norwegian kings played an important part in this process, by inviting priests and building churches. This process is traditionally seen as finished after Olav II Haraldsson (later known as “The Holy”). With this Norway was seen as a Christian country with its own laws for clergy as well as laws enforcing various religious actions and festivals. This naturally brought with it a lot of changes in the life of the operation, but the catholic church and the papacy did not have large amounts of power in Norway just because of this. The Norwegian kings where not crowned by a representative of the church nor did the church designate the bishops of Norway. In addition, laws regarding the church and the religious practices was still made by the Norwegian Kings rather than by the church.

Now let us go to 1108 and the holy land, or jorsal as the Norwegians called it. The Norwegian king Sigurd Jorsalfar traveled to Jerusalem to join the crusade and fight to expand the Christian holdings in Jerusalem. Now this event shows that by now the Norwegian Kings had joined the Christian community. Another important event showing this came some years before the crusades, in 1078 pope Gregor VII sends a letter to the Norwegian king offering help with the education of men in the Christian ways, so that they can help spread the faith among the population of Norway.

After the death of Sigurd Jorsalfar in 1130 the Kingdom and Norway was plunged into a century of internal conflict and succession crisis often just know as “the civil war” in Norway. The church was first introduced to this in 1163 when Erling Skakke tried to gain legitimacy for his son, Magnus Erlingson. Magnus Erlingsson was not a son of a previous king of Norway and he did therefore not have a claim to the throne of Norway. Erling therefore asked the Archbishop to crown his son. By doing this he strengthened the claim of his son, but he also increased the power of the church, from now on it was expected that the king of Norway was crowned by the Archbishop.

Magnus ruled for 21 years, before he was deposed by Sverre Sigurdsson. By deposing Magnus, Sverre gained an enemy in the church and this would not improve as time went. When the current archbishop died two years after Sverre deposed Magnus the church sent a new man to become archbishop. Sverre and the new archbishop, who was called Eirik, quickly became enemies and Eirik refused to crown Sverre as the King of Norway. The conflict quickly escalated when Eirik demanded that the catholic church should have control over all the churches in Norway, and not just the ones build by the catholic church. The conflict once again escalated when Archbishop Eirik chose the new bishop in Stavanger. Sverre disagreed with the choice, stating that the bishop should be elected trough an agreement between the church and the people. The case ended with a win for Sverre although it did not las long because the year after the very same man was chosen as bishop of Oslo. The biggest problem was when the archbishop wanted to increase the amount of men in his retinue. The king claimed that the archbishop had no need for a retinue, after all who would dare to attack the church? The archbishop on the other hand claimed that it was a matter of prestige because what would other kings think if the archbishop could not decide who to feed and protect? The conflict ended when Sverre threw the dice and demanded that the archbishop disbanded his retinue or else the extra men could be killed on sight. This forced archbishop Eirik to flee, which forced the remaining clergy to support Sverre and crown him. This therefore lead to internal peace between the church and the king. The relations between the pope and the king of Norway was about to get a lot worse. The pope sent a papal bull to Eirik granting him the right to excommunicate any person that defies the privileges of the Norwegian church. As a result, Sverre and the bishops supporting him get excommunicated, first by Eirik and then later by the pope himself. In 1198 this was followed up with a letter to the Norwegian clergy warning against helping Sverre in any way. At the same time Eirik returns to Norway, this time leading a warband knowns as “baglerne” and now with the support of many of the Norwegian nobility that previously supported Magnus Eringsson. The war between Sverre and baglerne lasted for six years. It ended as a victory for Sverre, but the remaining of baglerne is spared, as long as they swear fealty to king Sverre. The victory is short for Sverre because a few months after baglerne surrenders Sverre dies. By this ends the conflict between the church and the king, and with it the century of internal conflict.

To solidify the peace between the church and the kings a cardinal was sent to crown the new king of Norway. The new king was Håkon Håkonsson and he had a goal to unify all the laws of the country into one law, instead of the numerous regional laws that was present when he came to power. As a part of this comes the laws regarding the church. These where numerous and to get the support of the clergy for his new law Håkon had to make many concessions among them the old question regarding the church’s retinues, and thus allowing the churches power to grow. Large parts of the Norwegian nobility were discontent with the power the church received in the new law, and when Håkon dies and his 12-year-old son inherit the throne they begin taking actions against the church. Rumors about the noble’s plan to remove the rights of the church spreads and the clergy acts first. They threaten to excommunicate anyone who tries to remove the privileges of the Norwegian church. Despite this peace reigns, at least for now.

The peace is quickly broken as the nobility begin to take away the privileges of the church. As promised the church responds with excommunicating the men responsible for the laws. One by one the privileges are revoked and one by one the nobility excommunicated. The king, and his regency council, responds by threatening the clergy to support him and banishing the archbishop and the clergy that do not. Many of the clergy end up supporting the nobility and when one of the most important of the nobility dies he is still buried in a graveyard, despite being excommunicated. The conflict ends when the archbishop dies and the church loses most of the privileges they got from Håkon Håkonsson.

In the end, I just want to say thank you for reading and I hope I answered your question. I also hope that my English is understandable, as it is not my first language. If something is unclear or you just have any questions please ask.