about to the northeast. In 1383 the Holy Blood of Wilsnack became a famous pilgrimage site, while Dietrich Man was bishop. From the 14th century onwards, the Havelberg bishops also used Plattenburg Castle as a summer residence. After long-lasting quarrels with the mighty Brandenburg prince-electors, the Premonstratensian chapter finally gave in to transform Havelberg into a collegiate church (Stift). From 1514 onwards the deans of the cathedral were appointed by the Margraves of Brandenburg. In the course of the Protestant Reformation, the Bishopric of Havelberg turned Lutheran and from 1554 was administrated by Joachim Frederick of Hohenzollern, son of Elector John George of Brandenburg. The Bishopric was finally secularised and incorporated into Brandenburg in 1571. Its annexation was complete, when Joachim Frederick succeeded his father as Brandenburg elector in 1598. Bishops References Jürgen Schrader: Der Flecken Calvörde – Eine 1200-jährige Geschichte. Göttingen: Verlag Die Werkstatt, 2011, p. 54. External links Bishopric of Havelberg at GCatholic.org Bishopric of Havelberg at Catholic Hierarchy 946 establishments 1598 disestablishments in the Holy Roman Empire Former states and territories of Brandenburg Roman Catholic dioceses in the Holy Roman Empire Former Roman Catholic dioceses in Germany Prince-bishoprics of the Holy Roman Empire in Germany