OK, so first off, here’s my li’l world in general in 1457:

Were I to pan out more, you’d see Muscovy as a big ol’ blob on the other side of Lithuania. I’ll explain the craziness that’s going on in a sec.
Here’s a closeup of me, as Brandenburg. I’ve got my starting three provinces (Brandenburg, Potsdam, and Ruppin), as well as Neumark, Hinterpommern…and hey there, is that Ostpreussen? Yes, yes it is. No idea if I’ll be able to hold it, but for now, it’s mine:

So here’s the crazy stuff I did in my “one more hour” last night.
First off, I’d fabricated a claim against Anhalt, back when it was just a little province that wasn’t much. Well, then, Anhalt became part of Magdeburg, and Magdeburg formed an alliance with Saxony and the Hansa, which made them more than I could handle by myself, obviously.
Saxony had gotten worrisome, too. They’re not just Saxony: Thuringen and Wittenburg are their vassals. That made them a thorn in my side.
So my claim against Anhalt was in danger of expiring (I’ve had that happen before, I think) and I took one more look at it before resigning myself to dealing with them diplomatically if I could. Hey look! This time it says Poland will join me. Bohemia too! And as I’d learned, where Poland goes, Lithuania usually shows up. Well. Let’s pick this fight. I declared on Magdeburg (which is the provinces of Altmark and Anhalt). My allies agreed. Their allies agreed. Let’s have a war!
It really wasn’t that huge a deal. I easily subdued Magdeburg, and the combined arms of Bohemia, Poland, and Lithuania not only kept Hansa at bay, but they also utterly occupied (I helped!) Saxon provinces. I let the war go on a bit and collected money from both Saxony and the Hanseatic folk in separate peaces, and then made Magdeburg my vassal! So woohoo! When you look at that map, Altmark and Anhalt are my subject provinces.
From there, I set about raising my relations with them to get them to 190 so that in 10 years time I can annex them painlessly. While that was going on, Poland called me to arms in their fight against the Teutonic Order. They wanted Chelmin, so I thought maybe I could sneak Danzig from them. No such luck. They landed 14,000 men in Danzig before I could get there.
So…I took the next best. I took Ostpreussen, which I’ll need to form Prussia anyway.
Meanwhile, Hungary joined the fight as allies of the Teutonic folks. Bad move, Hungary. Rather than fight the weakened Polish army they’d smacked around when I started the game off with a war, this time they ran into a Polish army backed up by the might of Lithuania. SO…right now the Poles and the Lithuanians are giving them whatfor.
In the meantime, though, I’d also captured Marienburg, because I’m a good ally.
But then I started thinking. Poland could end this war at any time and take whatever chunks of Teutonic Order they want. I certainly would have that coming to me, for the way I’ve abused them diplomatically in war treaties. So I did something either really clever or monumentally stupid: I made a separate peace with the Teutonics. They ceded me East Prussia, I gave them back Marienburg, and sent the troops home.
So…I’ve got a valuable province–East Prussia–but no land route to get there, and only a tiny navy that consists of 4 barques. I’m already trying to core them at considerable expense, but still. I can’t imagine Poland is particularly thrilled about me taking what I’d like for me and mine there.
And so that’s where we stand!