Verden ( state ) The historic territory of Verden ( ) emerged from the Monarchs of the Frankish Diocese of Verden in the area of present - day central and northeastern Lower Saxony and existed as such until 1648 . The territory managed by secular lords for the bishops was not identical with that of the bishopric , but was located within its boundaries and made up about a quarter of the diocesan area . The territory was referred to at the time as " Stift Verden " or " Hochstift Verden " , roughly equating to Prince - Bishopric of Verden . This territory described in local sources today incorrectly as " Bistum Verden " ( " Bishopric of Verden " ) and , in 1648 , was given the title Principality of Verden , sometimes referred to as the Duchy of Verden . Location . The territory of Verden covered the eastern part of the present district of Verden ( its border ran between Langwedel and Etelsen ) , the southern part of the district of Rotenburg ( Wümme ) and parts of the districts of Harburg and the Heath district ( Heidekreis ) . History . Foundation . The Diocese of Verden was founded around 800 in Verden upon Aller as an episcopal see and initially belonged to the Ecclesiastical Province of Mainz . Originally held in personal union with Amorbach Abbey in the Odenwald , by the 9th century the bishopric had become a political football for the regional nobility . For example , the Amelungs promoted their favourite monks from Corvey Abbey to the episcopal throne . High Middle Ages . In the outgoing 10th century ( A . D . 985 ) Emperor Otto III , represented by his mother , Empress Theophanu , granted the bishop of Verden market , minting , taxation and ban privileges in the " Sturmigau " – as the region of the present district of Verden and the old district of Rotenburg was then called . These privileges formed the basis of a future prince - bishopric , which materialised with the carve - up of the old Duchy of Saxony in 1180 . Prince - Bishop Tammo of Verden gained for about a quarter of the diocesan territory , where the see held already considerable privileges , the territorial princely power , establishing the Prince - Bishopric of Verden . In 1195 Prince - Bishop Rudolph I founded the castle of Rotenburg upon Wümme as a stronghold against the neighbouring Bremen prince - archbishops . Later the castle took on the function of a prince - episcopal " Residenz " . Since the Investiture Controversy in the 11th and 12th century the cathedral chapter s used to elect the Catholic bishops in the Holy Roman Empire . Thus Verden prince - bishopric was an elective monarchy of imperial immediacy within the Empire , with the monarch being the respective bishop usually elected by the chapter and confirmed by the Holy See , or exceptionally only appointed by the Holy See , which happened in increasing frequency in Verden . Papally confirmed bishops were then invested by the emperor with the princely regalia , thus the title prince - bishop . In the early 13th century the Pope was increasingly involved by the local prince - bishops in regional affairs . From the 14th century it was hardly possible to hold out against the papal commission , which led to a strengthening of the influence of the cathedral chapter ; whilst the many prince - bishops were now seen as " Landfremde " or alien , who lacked local support because they were not elected by the chapter but only appointed by the pope . Since the early 16th century the prince - bishopric belonged to the Lower Rhenish – Westphalian Circle ( colloquially : " Westphalian Circle " ) , a fiscal and military subsection of the empire . Verden sent its representatives to the " diets " of the empire and the Imperial Circle . At times the prince - bishops ruled in personal union the Prince - Archbishopric of Bremen . In order to maintain the two seats in the diets the sees of Bremen and Verden were never formally united in a real union . The same is true for the collectively governed Duchies of Bremen and Verden which emerged in 1648 from the secularised two prince - bishoprics . Principality of Verden . In 1648 the bishopric was finally secularised as a result of the Peace of Westphalia . It became a principality and was transferred to the Swedish crown , whereby the existence of the " Stift " and the bishopric came to an end . It lasted from 1648 to 1712 , with a break from 1675 to 1679 , ruled together in personal union with the territory of the former Prince - Archbishopric of Bremen as the " Duchies of Bremen and Verden " ( formally the Duchy of Bremen and Principality of Verden ) with their capital in Stade . For the further history see : Bremen - Verden .