Ah, at last... Denmark defeated, unprecedented income, happy vassals and-KABAM!

[Swedish Steel!]

My king dies! now my income was cut to a quarter of its (for my poor Sweden) former glory because the vassals dislike his son. This isn't even enough to permanently maintain the Rus mercenaries and it'll take me four times as long to construct new improvements, which also ruins my plans to construct castles in Finland and Curland in preparation for my two-front war with Poland to wrest control of the Baltic. In other words, what can I do to prevent this in the save before the king dies?! I need those vassals to like my new king just as much as they liked the last one.

PS. I didn't know how easy assassination was until I tried it. Just 50 gold? no time limit to retry? a pitiful piety loss if your name gets discovered? All I need to do now is find out how I can create claims to diploannex territories instead of fighting for them (I was never much of a diplomat in these sorts of games...). Within the space of 150 gold the king of Denmark was dead and two battles later the next king has become my prisoner! he didn't want to pay the ransom, so I'm letting him rot until he dies, should I do so or is there an opportunity I'm missing? (I can check being an opportunist however ).

 

[CirMag]

My king dies! now my income was cut to a quarter of its (for my poor Sweden) former glory because the vassals dislike his son. This isn't even enough to permanently maintain the Rus mercenaries and it'll take me four times as long to construct new improvements, which also ruins my plans to construct castles in Finland and Curland in preparation for my two-front war with Poland to wrest control of the Baltic. In other words, what can I do to prevent this in the save before the king dies?! I need those vassals to like my new king just as much as they liked the last one.

The largest factor may be the long reign bonus of the prior king becoming a short reign penalty under the new king. That is cured by time.
Other significant factors to vassal relationships are the traits of your king, the traits of vassals, and diplomacy, that is most easily controlled though proper educating. You should teach your heir.

Remember those relations effect troop and tax levels. If relations are negative, taxes are decreased. With levies the relations acts as a modifier in addition to the laws.

 

[zedyue]

make sure the moment your king dies, you pause and have your son transfer vassals to all the people who should have them. Such as if a guy owns a province but the bishop of his church is your vassal, he will HATE your son. But if your son gifts that bishop to him, he gets the +20 vassal bonus PLUS the negative modifier is removed. I always try to have a few duchies and such here and there under my vassals so that when I die my heir can gift them back.

After the first 4-5 years or so as heir, if you kept it stable you are pretty much set up for a stable lifetime. The worst part is when you have it going at +5 speed and just doing events and your king dies and you zip ahead 30 days and everything rebels at once.