No Vassalation Option Despite Satisfying (I think)

[unmerged(1218)]

I am England trying to vassalize Hanover. Relationship 200+. No option offered. I think we are same religon (though hard to find in interface). We have Royal Marriage. My understanding is we do not need common border for this.
What am I missing?

BTW I am using an index into the manual, FAQs, and searches of this site before I ask questions. So please bear with me.
Lin

 

[unmerged(1218)]

Figured out No Vassalation

Discovered pop up help on diplomatic offers. Need military aliance. Thanks, Sorry.

 

[unmerged(1218)]

Ack! Maybe not!

Hanover says in alliance with Brandenburg and need to go to head of alliance to offer alliance. Go to Brandenburg and cannot offer alliance! (ack!)
I confirmed via Ledge that Brandenburg is leader of alliance. Must I have a certain quality of relationship? But I don't even have ability to offer them letter of introduction.
They are are in a war in case that matters.
Help appreciated,
LIn

 

[unmerged(548)]

They are are in a war in case that matters.

Yes it does, once they are at peace you will have a button to ask to join their alliance.

This btw is another thread should be in the FAQ forum, not the hardware issue Support forum.