Well with the new patch I decided to end my Poland campaign, a bit early and I could of just stuck with 2.04 for awhile to get further but eh, about as good a time as any to end it.
Synopsis:
Started as a Count (well the Slavic version of count) in Poland before it existed, managed to rather quickly rise to Ducal level which allowed me to push to forming the Kingdom of Poland relatively quick. Sat as that for a couple generations before I randomly had a Suomenusko kid take the throne which started causing issues (As it would in a Slavic dominated land), but managed to hold together for a bit and got the "Christian pilgrims" event or something that sparked him on the path to Catholicism and he ended up converting. This pretty much got him kicked out from being king(To a Slavic Duke of my Dynasty) and I went back to being a Duke.(still Christian though) So backed off for awhile and managed to regain my strength and convert my vassals to catholic, the throne bounced around between the guy who took my throne and some Piast wanker (The Piast dynasty did not last afterwards...) a couple times before the King died and I struck. Took the throne and quite effectively converted the rest of the nobility to Catholicism.
Being able to switch to Ultimogeniture succession with only light crown laws is overpowered as shit by the way and that really secured my Dynasty, Fuck you Gavelkind.
After getting the land firmly under Catholic (and really my King's) control it basically became a matter of picking my battles, usually with pagans. My first campaigns were usually against the various Baltic coast Pagans which eventually allowed me to add the King of Pomerania to my repertoire of titles. Lithuania was also a big enemy, mainly due to the fact that for a good long while they weren't just the Kingdom of Lithuania but the Kingdom of Lithuania & Sweden and they certainly liked to throw this weight around in regards to Poland, rescue by Knighthood orders was required a couple times. Eventually, though, they split up (Being forced Gavelkind as Pagans tends to cause that) and I grew powerful enough to just swat them upside the head with a newspaper whenever I felt like it.
If you notice in the picture, Hungary happens to be Sejuk, I'm not entirely sure what happened there, at some point the entirety of Hungary just ended up under the Sejuks and stayed there, they never really caused a threat to me (though I imagine they would of eventually) and I didn't really poke them much (though during a rebellion I stole myself a bordering province, heh. The whole map was pretty chaotic however except for a few factions, France was always a mess, everything east of Poland, Hungary, and Lithuania was a complete and utter mess, even after the Sejuks took a sizable chunk of it. The Eastern Roman Empire always looked like it was losing ground to the Muslims, I think by this picture it had managed to resurge a bit. (abit with falling into complete civil war quite often IIRC) East Francia sort of blended into the furniture I think, though it looks like they pushed a fair bit south, but they definitely did not have any sort of conflict with me however and never picked fights with the Pagans on its borders. (Which allowed me to to push west past the Elbe in places)
So yeah, fun campaign, not sure if I'm going to immediately jump into a new Campaign yet, this one had a few month break in the middle of it and only recently got back into it. (Probably could have made it to 1453 if I hadn't taken a break, but eh)