Holstein is the emperor. I am France. The objective for me is to try and dismantle the empire. I allied Munster, Salzburg and Saxony. Verden was allied to the emperor, which is Holstein.
I declare war on Provence, they have no allies and are in the HRE. Theoretically this means that to dismantle the empire, all I have to do is siege down Verden's and Holstiens capitals down. Okay, that's fine.
This is where Brunswick comes in. The emperor added them in during the war. So you'd expect me to declare war on them right as well?
Well there's a mechanic that doesn't let you do that for some reason. So they can add electors during a war but you can't kill those electors..... in a different war?
*sigh*