Mediatisation

Mediatisation is the loss of imperial immediacy. Broadly defined it is the subsumption of one monarchy into another monarchy in such a way that the ruler of the annexed state keeps his sovereign title and, sometimes, a measure of local power. For instance: when a sovereign county is annexed to a larger realm, its reigning count might find himself subordinated to another sovereign ruler, but nevertheless remains a count of sovereign rank, if not actually fully sovereign in fact. His subjects owe allegiance to the higher prince through him, and so his sovereignty is said to be mediatised, that is, rendered intermediate.