How does one gain control of a source holding? For the purpose of divestiture and recognition ceremonies.
I am thinking that an espionage action, adventure action or realm spell is needed to pinpoint the physical location of the source. Then control of it can be taken by force of arms or through an adventure - enabling the controlling regent to perform first a divestiture and then recognition.
Or is this too easy? Perhaps an adventure action must be used to overcome the inherent magical protections of the source and gain control - the protection could be a guardian, a forest that everyone gets lost in, etc.