Just thought I'd share the progress on my Saxony game, my first game started with Charlemagne. The imperial name is perhaps a bit uninspired, but it has a nice ring to it, I think. Big highlights of my progress was using Theoderic's one subjugation on Denmark, and then his grandson's on a unified Lithuania. Along, of course, with some tricky wars vs Charlie early on. I only expanded into pagan territories until I could withstand the Karlings, then sat tight for the most part, raiding and upgrading. Once I became Fylkir I started expanding into the low countries to weaken France and get some ship levy for further raiding, despite the feudal vassal penalty (still tribal.)
I was lucky in that good ole Charles never formed Francia, but he had a monstrous West Francia for a while. Then things were chaotic for decades until it settled with France, Bavaria-Italy, and a fluctuating East Francia and Middle Francia in between, which were the only remaining Karling headed realms. Aquitaine is a third new dynasty, but it's currently losing a war vs France and Bavaria for the king of France's claim on it. Oh, and that green bordering the Umayyads is the ever enormous caliphate, naturally, though now held by the Ali dynasty.
Currently, my entire desmene is stone hillforted up, along with most of the duchies close to Saxony proper. All my high chiefs have the tech for stone hillforts in their capitals, but a lot of their other lands do not. Tech spread is limiting me more than gold here. I'm thinking of waiting until crusades are unlocked, then starting a great holy war for Bavaria or France or something. Then wait for new administration etc to wear off, and then adopt feudalism, tech spread be damned. At least that way I would have a lot more existing feudal vassals ready for the transition.