from where he administered the territory. As a result, it is probable that the name of the Principality of Calenberg emerged during this time. Unification with Göttingen Between 1442 and 1463 William succeeded in taking over the rule over the Brunswick Principality of Göttingen. Although unification with Calenberg initially came about purely by chance, it lasted nonetheless. In order to distinguish the two areas which were physically separated by the foothills of the uplands in the Leine valley, Calenberg in the north was usually referred to as Unterwald ("Lower Forest"), whilst the Göttingen region was called the Oberwald ("Upper Forest"). When in 1473 William also inherited the Principality of Wolfenbüttel from his brother Henry who had left no heirs, he ceded sovereignty over Calenberg to his sons William the Younger and Frederick III, known as "the Restless" or "Turbulentus". After the death of William the Victorious in 1482 both sons shared the regency. In an agreement dated 1 August 1483, however, they split the rights of use (Mutschierung). The younger son, Frederick the Restless, was awarded the rights of use over Calenberg and Göttingen, and his brother William the Younger was awarded the rule over Wolfenbüttel. Nevertheless, in 1484/85 William deposed his brother Frederick and declared him insane. The reasons for his removal are debated; perhaps by his participation in many armed conflicts, Frederick was seen to pose a threat to Welf rule in Calenberg and Göttingen. So William succeeded - albeit only briefly - in re-uniting the entire territory of the principalities of Calenberg, Brunswick-Göttingen and Brunswick-Wolfenbüttel. After Frederick's death in 1495, however, William again divided his territories and left the Principality of Brunswick-Wolfenbüttel to his elder son Henry V. Under Eric I, Elisabeth and Eric II The younger son, Eric I received Calenberg and Göttingen and thus founded the Calenberg line of the House of Brunswick-Lüneburg. In the new territory so formed, the name Calenberg was increasingly used for both parts of the state. For the period under Eric I and his son, Eric II, however, the name "Principality of Calenberg-Göttingen" was also used a lot. The principality had separate parliamentary Estates and separate councils for each part. The chancellery for Unterwald was established in Neustadt on Rübenberge and that for Oberwald in Münden. There were also separate residences, lordly castles or manor houses and palaces in each town as well as separate repositories for their records. Under