How to make core on Warsaw playing as Poland?

[PawelK198604]

I not played the game for a while and forgot some things. I want incorpoarte Mazovia into Poland and completing mission regarding this.

[Snizzlet]

It's a diplomatic action, in the influence category

[Fellini_Fiend]

After ten years and 190 relations diplomatically annex the vassal. It’s that simple.