For heavens sake.
I as England, hold the typical stuff, England, France, Ireland, number of smaller countries. I am also married to Queen of Naples, Albania and Provence so there is a bit of a habsburg situations forming for my heir.
Now what happens:
- bank of Medici declares war to Naples. I am automatically called to the war due to the marriage union.
- France for some reason joins the bank of medici. I am now at war with France who I had a personal union with.
- Personal union breaks, my heir becomes king of france.
- Some random Northumbrian dude becomes my new king of england for some ******* reason. The old king still holds ireland and the other dominions and fiefdoms.

