My latest Whiteshirt run, I think I am finished with this now but might play on.
Very early on I captured Mercia and Anglia to form a powerful Danelaw. I then invaded Scotland, ruling it in PU for a while but now it is just a title that I keep but is titular. I actually rushed Westfalia when the duke of Angria declared independence from Louis 'the German', and then picked up Prandhimr to reform the faith around 900AD. The kingdoms of Denmark Norway and Sweden were all independent of me until after I formed Daneland in 1100, after which I used my inherited claims to take all three in two wars.
My father, King Sölvi, after conquering the Nords, the Danes and the Swedes, decided that Iberia was in need of saving. He thusly invaded Andalusia and between him and my current character, King Grímr, conquered all of Iberia. However I don't want to become an emperor and that put me over the vassal limit, so I granted the kingdoms to my dynasts, not before converting much of Iberia to Astaru though
An interesting thing to note is that because I've done so well this game, the Catholics have done quite poorly. At one point, Byz managed to vassalise Bavaria, and consequently, Bavaria went orthodox. I have no idea why Italy is Orthodox though, it has only happened this generation. Also, yes Francia formed, but it isn't as powerful as you might think. Most of it is split between the two kingdoms, so the emperor is about as powerful as his vassal kings. The only reason why it still exists at all is that up until now, I have decided not to take France out. Might rectify that now and see if I can help unite Christendom by destroying the Catholic faith.