I was reading through some history files on CK2 and it claims that a number of Wessex kings up until about 600-700 AD were Norse, and then they converted to Christianity.
Is this true? I thought they converted to Christianity almost instantaneously when they migrated from Saxony so I didn't expect this.
The Angles, Saxons, and Jutes who all eventually coalesced into the "Anglo-Saxons" were a part of the broader Germanic world and had their own local analogues to the famous deities in the Norse Pantheon, Odin, Thor, Frey, and so on.
Upon their arrival in Britain they brought their own religious traditions with them, and supplanted the native British Church (it did not however disappear entirely). Their process of conversion lasted, according to the venerable Bede, from the early 600's to the 680's. During this period there were many conversions and lapses in the population. In many cases a king would convert, but following his death, still pagan elements took power again.
According to Bede who is our only textual source for most of this process, the last pagan king ruled on the isle of Wight and was destroyed by a Christian invasion. The first king to accept Christianity ruled Kent.
If you've got any follow up questions I'd be happy to answer them
If you'd like to read about some of the events of this conversion period, take a look at some of my older posts
This one is pretty broad on the process of conversion in general
This on the last pagan kingdom in England
Here I touch on the relationship between Anglo-Saxon and Norse paganism