Basically, I had all the Swedish lords (literally ALL) imprisoned in Koenigsberg. After I teamed up with the Russians and took over their last city, I decided "Hmm, why not release all of the lords for free? I mean, there is a chance they'll defect to my nation, right? Riiight?" I ended up with 20 relationship with Sweden after a full-blown -100 relationship from recruiting Swedish Reiters from their patrols (imprison, convince, pray they won't escape in the night) by hitting their feet with a carbine butt. 'Cause that's the only blunt weapon I got! The rest of my weapons were a balanced Scottish broadsword and a balanced hussar lance at the time. After Sweden died, my relationship with my nation (Poland) in -1! A glancing -1! Which means I can't enter even my OWN cities/castles without having to sneak in! 
