Religion

The age of conversion
The Viking Age was a period of considerable religious change in Scandinavia. Part of the popular image of the Vikings is that they were all pagans, with a hatred of the Christian Church, but this view is very misleading. It is true that almost the entire population of Scandinavia was pagan at the beginning of the Viking Age, but the Vikings had many gods, and it was no problem for them to accept the Christian god alongside their own. Most scholars today believe that Viking attacks on Christian churches had nothing to do with religion, but more to do with the fact that monasteries were typically both wealthy and poorly defended, making them an easy target for plunder.
The Vikings came into contact with Christianity through their raids, and when they settled in lands with a Christian population, they adopted Christianity quite quickly. This was true in Normandy, Ireland, and throughout the British Isles. Although contemporary accounts say little about this, we can see it in the archaeological evidence. Pagans buried their dead with grave goods, but Christians normally didn't, and this makes it relatively easy to spot the change in religion.
As well as conversion abroad, the Viking Age also saw a gradual conversion in Scandinavia itself, as Anglo-Saxon and German missionaries arrived to convert the pagans. By the mid-11th century, Christianity was well established in Denmark and most of Norway. Although there was a temporary conversion in Sweden in the early 11th century, it wasn't until the mid-12th century that Christianity became established there. As part of the process of conversion the Christians took over traditional pagan sites. A good example of this can be seen at Gamle Uppsala in Sweden, where the remains of an early church stand alongside a series of huge pagan burial mounds.