By the way I'm King of Norway now, having started with the Ynglings of Ostlandet. My original king was awesome with something in the neighborhood of 2000 prestige and 500-something piety, and I was planning to do a prepared invasion on one of the French kingdoms or maybe something in Britain, but he died in battle ;c
I'm Yngling King of Norway, too, from Rogaland. Got conquered by King Fairhair of Ostlandet pretty quick, but then married my heir to his daughter and pushed her claim to the throne via faction (at the time, I was the strongest Duke by far) when he died. He had done a pretty good job, taking all of modern Norway and large chunks of Lithuania and Northern Germany (plus Iceland, but meh). My grandson managed to hold the place together after his mom passed on and left him the kingdom. He did so by triggering a subjugation war for Sweden which lasted twenty years and kept everybody's army population low. Rebellions popped up all the time, but they were easily crushed as part of the ongoing conflict.
Finally, the King of Sweden had no choice but to give up, and all of Scandinavia was united under a single banner. We could only enjoy it for two days, however, because the Lithuanian High Chief and his son spent the whole previous era building up power and screaming for blood. On their latest bid for independence, the entire Kingdom imploded. Not even as a result of Gavelkind or anything.
Iceland, meanwhile, because of the trouble involved in getting its army all the way to Sweden, was left to its own devices and is now home to the two richest counts in all of the Norse lands. They've singlehandedly been preventing England from unifying with their constant raids.