Changing Province Ownership

I had a look at a guide in the Scriptorium, and I succesfully removed Deva from Britannia and gave it to the rebels. However, I tried to remove Eburacum from Britannia and give it to rebels, but using the same techniques as before it didn't work. I noticed Eburacum has a Family Member in it, and I tried to make him the rebel general. Could this have anything to do with the problem?

Could well, be. Instead of trying to make him a rebel general which leads on to all sorts of other dependencies, it would be easier to move him out of the settlement or delete him and then copy an existing rebel captain there instead?
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