My first attempt at grabbing as much territory as possible in 1.3, the great british empire!
I got the aztecs as my vassal as well, but I wasn't able to integrate them in time. In retrospect, I should've just cored their provinces manually, for glorious all-red americas. I clearly failed pretty miserably at grabbing territory in more respects than just that; I could easily have grabbed huge amounts of china and india, as well as the holy lands, but I kind of ran out of steam a ways through.
Started out the 'usual' way to start britain "seriously" in 1.3; win the HYW, then vassalize portugal and spain, for maximum colonization goodness. But then I hit a snag, when I attacked Burgundy, who had apparently been doing pretty well for themselves... their armies crushed mine completely in all equal engagements, and it took me
42 years to finally win the war. In retrospect, I should've massed above my forcelimit in troops at their border before attacking (or peaced out early), but I was arrogantly convinced that they would pose no challenge at all.
After that massive setback to my goals (42 years doing essentially nothing), I was ready to abandon the game. Didn't help that Henry VI had ruled to 1485 before he finally croaked. But when
the Brutal British Conquest of Artois finally ended, the lancaster line ended with it, and stepping up to take the throne was
William III von Habsburg, whose title should've been 'the fucking amazing', because his stats were 5/6/6.
I got embroiled in a bunch of other wars in europe, as the HRE didn't take kindly to my aggressions east of france, but after burgundy it seemed nobody was a match for our armies. I guess it helped that I got defensive mentality, for the morale boost, after having learned my lesson against the burgundians. About 100 years of that nonsense passed, during which I vassalized a three electors, but was unable to get myself crowned emperor in time for some newly born bohemian king to grab the mantle and rule for some 60 years, which was enough time for him to eventually form the HRE without me being able to stop him, even if I did grab huge cunks of it.
Then, as I was about to give up out of frustration again, out of nowehre I got involved in a war with austria, hungary, and huge chunks of the rest of europe. I was confused, since I didn't even get any kind of notification that I was in a war, and as I looked at the war-goal it said "take moskva". Eh? Turns out, Russia had defaulted to a PU under me (presumably because I had more prestige than austria?), and I was now involved in a war over its throne! Well, it was a short-lived war with the massive russian army helping me out, and in time I would be able to PU austria as well.
Integrating russia was pretty obnoxious, thanks to their various negative modifiers such as heretical religion, but I managed to do it thanks to one of those random +60 relations events.
In the end, I'm fairly satisfied with my empire. 0% overextension, no revolt risk, and 86% catholic. Could've done a lot better if I was more aggressive, but for 90% of the game I was focused entirely on europe, and by the time I was satisfied that it was under my control it was too late to grab large parts of lands elsewhere anyway. I did grab some of india, but eh.