Burkhard von Weisbriach was an ecclesiastical principality whose capital was the former city of what?
Archbishopric of Salzburg The Prince-Archbishopric of Salzburg (German: "Fürsterzbistum Salzburg" ) was an ecclesiastical principality and state of the Holy Roman Empire. It comprised the secular territory ruled by the Archbishops of Salzburg, as distinguished from the much larger Catholic diocese founded in 739 by Saint Boniface in the German stem duchy of Bavaria. The capital of the archbishopric was Salzburg, the former Roman city of "Iuvavum ".
Principality of Bayreuth The Principality of Bayreuth (German: "Fürstentum Bayreuth" ) or Margraviate of Brandenburg-Bayreuth ("Markgraftum Brandenburg-Bayreuth") was an immediate territory of the Holy Roman Empire, ruled by a Franconian branch of the Hohenzollern dynasty. Since Burgrave Frederick VI of Nuremberg was enfeoffed with the Margraviate of Brandenburg in 1415/17, the Hohenzollern princes transferred the margravial title to their Franconian possessions, though the principality never had been a march. Until 1604 they used Plassenburg Castle in Kulmbach as their residence, hence their territory was officially called the Principality of Kulmbach or Margraviate of Brandenburg-Kulmbach until the Empire's dissolution in 1806.