Ever since its formation the noble assembly of Transylvania assumed rights of decision in issues connected to landed possession, and was also empowered to withdraw rights of property and possession. Available data show the most powerful Transylvanian nobility in this age as located in the counties of northern Transylvania. The complex ethnic and administrative landscape ofthe province required an assembly structure larger than that of the seven “voivodal” counties, including representatives of all privileged estates of the former “duchy” of Transylvania. Such a representative body could however only be summoned by the king, the only direct and recognized authority over all administrative units of this territory. Possibly this was conceived as a way to rebuild the unity of Transylvania starting at the level of its representative structures and, at the same time, as an effective formula to control the nobility of the counties.