Playing as Russia, I managed to break the Golden Horde fairly early on (before 1500s). I then conquered Lithuania who had broken free from Poland, and set up the buffer state of Polotsk, force vassalised Riga, and diplo-vassalised Ukraine who had revolted from southern Lithuania to complete the barrier against whoever had the upper hand in the HRE at any point. I gave Riga and Ukraine my Lithuanian provinces so they would be able to have a decent army.
In Asia when I smashed through the various Khanates I ended up going over the BB limit which caused Riga to break free while I was at war with the Ottomans around the mid 1500s. My intention was to free the Balkans from them, but I ended up getting them to release everything they could in Europe. I revassalised Riga later and then gave them Samigota and the other provinces that Brandenburg controls in this picture.
Click the pictures to get a world map.
1541: I have Polotsk, Ukraine, Novogrod, and Georgia as vassals here, and no allies apart from them. (BB around 55)
I had a couple of wars with Ming when I reached them and got them to release the other Chinese revolters, Qin ended up controlling northern China, while Ming had the middle and Japan invaded and later annexed Wu in the south.
I spent most of the 17th and 18th Centuries trying to force a balance of power within the HRE, first warring with Brandenburg, then Bavaria when Brandenburg got inherited by them, and finally Austria. Around 1775 I managed to force Austria to loose enough territory so that they were of equal power to the combined Netherlands & Bavaria. When I was warring against Bavaria I managed to get them to convert to Orthodox, and as they where the emperor they started converting the HRE states to Orthodoxy. I think in the end only Austria, Wurtumburg and The Palatinate where Catholic.
The Prussian region changed hands so many times this game, first Poland conquered it, then Bohemia and Brandenburg fought over the area while partitioning Poland. It changed hands again to Bavaria when they inherited Brandenburg, I forced Bavaria to release the Teutonic Order, which formed Prussia and soon after that they were inherited by Austria, finally being split between me and Bavaria in the early 1700s after a series of inconclusive wars against Austria.
I ended the game with Riga, Polotsk, Ukraine, Trebizoid, and Croatia as vassals, and Bavaria, Netherlands, and Castille as allies. I was disappointed that the only colonial revolter was Haiti which emerged in the Turk Islands after revolting from Great Britain. Elsewhere the Papal States had a very successful game colonising parts of Canada and South America, France rebounded after getting mushed by Austria and conquered the Middle East, although I wish they had reconquered Normandy and Orleans as they weren't guaranteed or allied with anyone powerful. Castille, Portugal, and Great Britain got muddled up with where they were meant to be colonising in America, but that continent was rather peaceful. Austria went on a colonising spree in the Philippines taking up the slack from Netherlands. Lastly, at one point Sardinia had some small colonial holdings in Brazil, but they were eventually annexed by Portugal, Crete spent most of the game isolated in my sphere of influence with no-one interacting with them, and Naxos manged to hold onto their Greek lands and expand, with a small amount of help from myself.
1821: Riga, Polotsk, Ukraine, Croatia, and Trebizoid as vassals, Bavaria, Netherlands, and Castille as allies. (BB is 0)
My final stats were: second in income to Portugal (they had an epic CoT in Niagra), largest and most advanced army, and a respectable navy.
All my provinces had every building in them, with my manufactories and Regimental Camps being only built west of the Urals.
All my provinces Orthodox, and only 5 with a culture other than Russian in Asia, with my Georgian provinces having Georgian culture as well.
Turak