The Prince-Bishopric of Osnabrück is a state of the Holy Roman Empire from 1225 until 1803.
It is the territory of princely rule held by the incumbents of the Diocese of Osnabrück, therefore wielding secular and religious functions as prince-bishops.
It is named after its capital, Osnabrück.The still extant Diocese of Osnabrück, erected in 772, is the oldest see founded by Charlemagne, in order to Christianize the conquered stem-duchy of Saxony.
The episcopal and capitular temporal possessions of the see, originally quite limited, grows in time, and its prince-bishops exercise an extensive civil jurisdiction within the territory covered by their rights of Imperial immunity.
The Prince-Bishopric continues to grow in size, making its status during the Reformation a highly contentious issue.In the German Mediatization of 1803, the Bishopric is dissolved and the secular or temporal power given to the Hanover branch of Brunswick-Lüneburg; the see, the chapter, the convents and the Catholic charitable institutions are secularized.
The territory of the see passes to Prussia in 1806, to the Kingdom of Westphalia in 1807, to Napoleonic France in 1810, and again to Hanover in 1814.With the end of the prince-bishopric also the future of the diocese becomes unclear.
Klemens von Gruben, titular Bishop of Paros in Greece, is made vicar apostolic of Osnabrück, and as such cares for the spiritual interests of the Catholic population.
The ordinary Latin (Roman) Catholic episcopacy is restored in 1824, but henceforth the bishops will no longer wield any temporal power.
