How can i give my half of Ireland to my brother which has the other half?

[GeneralisimoAR]

I want him to be King, so I need to give him my lands there.

He is an independent ruler.

thanks.

 

[prismaticmarcus]

and who/what are you?

 

[Nawjak]

I don't think you can give titles/vassals to other independent rulers, so you have two options:
A) Grant your half of Ireland independence and hope your brother conquers it
B) Conquer your brother, give him all the titles/vassals and then grant him independence; though you should be emperor before you attempt that

 

[Greifental]

Kill all your children and let him inherit when you die... Drawback: You have to play as him then.