Minden Cathedral, dedicated to Saints Gorgonius and Peter, is a Roman Catholic church in the city of Minden, North Rhine-Westphalia, Germany. From the year 803 AD, when the area was conquered by Charlemagne, it was the center of a diocese and subsequently became the center of a small sovereign state, a prince-bishopric (Hochstift) of Minden, until the time of the Peace of Westphalia (1648), when Minden was secularized as the Principality of Minden (which lasted until 1806).