Courtier with de jure claim

[Zuru84]

I am playing as a vassal.
I have a courtier with de jure claims according to duchy. I have declared war based on this claim.
I have won a war and he became independent vassal with this duchy.
What should I do to keep this duchy in my realm with this courtier as an owner of this duchy?
should I grant him any land title and after that declare de jure war?
After that I will still be his liege with his duchy in my borders?

 

[Sirrobert1]

If you press someone's claim, they only become your vassal if they are off your dynasty. If they are already a vassal, they stay your vassal, if possible (if you are a Duke, you can't have a duke as vassal, so if you press someone's claim for a Duchy, they become independent from you).

So, assuming you are a King, you should have given your courtier land (any land, a barony will do), before pressing the claim, than he'd stay your vassal. If you are a duke, he would never have been your vassal any way.

 

[Ruisuki]

I play ck2+ which i think the land given has to be equal rank of the title in question, and im not bout to fight for a county, or give away 2 duchies so I usually marry the claimant to my child and wait til the original dies so I can press it for my grandchild, of my dynasty. Only works for inheritable claims unless youre willing to risk having no direct control over the claimants court and risk the child dying based on potential incompetence. If doing the latter youd need to strong, of a kingly rank most likely and of the same culture or de jure liege. 3/4. Thats why pressing for family is so much easier.

 

[Tatterhood]

I believe OP also plays CK2+ since I've seen him post in that forum, so yeah you'd have to give him an actual duchy.

If you're an emperor you might be able to get him to accept vassalization. If you're a king you're out of luck since a duke will only accept vassalization to a king if he's a de jure vassal (in which case the claim war would've made him your vassal anyway).