Wikipedia
Afterlehen
An Afterlehen is a fief that the liege lord has himself been given as a fief and has then, in turn, enfeoffed it wholly or partially to a lesser vassal or vassals. The term is German. It is variously referred to in English as a mesne fief an arriere fief or subfief, under-tenure or mesnalty.
Within the Holy Roman Empire these mesne fiefs even became inheritable over time and could have up to five "stations" between the actual holder of the fief and the overarching liege lord.
An example of an Afterlehen is Rothenberg Castle in Bavaria, Germany.