Just finished up another great game of EUIII. I wanted a simple and relaxed game so I decided to play as Burgundy, whom I'd never played as before, and just focus on taking western Europe initially. I got off to a good but challenging start with myself, France and England often getting into wars with one another as the 3 superpowers of Europe.
I was nicely chipping away at France's territory when the game decided to throw me a curve ball as I was elected Holy Roman Emperor, I wasn't too happy about this as I wanted to avoid the messy politics of the HRE, but in hindsight the manpower was what let me finally overpower France. (Running the beta patch where manpower recovers much slower.)
Over the course of the second half of the 15th century I was drawn further into the politics of the HRE due to the allure of the bonuses of being the Emperor, reforms, and cores from Imperial Bans. I also had the powerful Castille in a personal union under me, and control over all of the major centres of trade, so everything was going great at this point.
Then the reformation kicked in and things got really messy, really fast. Trying to keep Imperial authority above 0% whilst members are converting during the reformation is fruitless so I decided I'd let it bottom out until things had cooled down. However in a bid to keep my position as the Emperor I had to get into several bloody wars to keep the Electors on my side, Great Britain and Scandinavia (first time I've seen the AI form it) were being a real nuisance, but I was ahead of most of Europe in technology thanks to my brilliant traders so despite the dog-pile that is war in the HRE, I managed to come out on top, even after converting to Protestantism.
The biggest loss of this period was my union with the newly formed Spain, who had grown hugely in power focusing on colonisation whilst the rest of Europe was battling it out for religious supremacy, and I just didn't have enough money to spam gift them whilst trying to keep HRE members on my side.
But by the end of the 1500s I had come out really well, I had a large amount of vassals in the HRE, and endless authority from going around converting Catholic nations thanks to Unam Sanctum, and managed to form the HRE just as the century came to a close. There wasn't much left of Europe outside my control at this point, just southern Italy and a few tiny French states. I went to war with the Ottomans to retake Greece for the Empire, which was hilariously easy despite their superior numbers as I had control over the Bosphorus Sound with my massive navy, a navy that hadn't existed 10 years prior.
I decided to stop at that point in the early 1600s as I was effectively unstoppable. I just love how you can go into this game with a clear plan of what you want to do, and end up doing things you hadn't at all considered. I think that will be my last game of Europa until IV is released, I may try a Sub-Saharan nation or Japan, but otherwise I'll be sticking to CK and Vicky in the meantime.