Plassenburg is a castle in the city of Kulmbach in Bavaria. It is one of the most impressive castles in Germany and a symbol of the city. It was first mentioned in 1135. The Plassenberg family were ministerial of the counts of Andechs and used as their seat the Plassenburg. The House of Guttenberg, a prominent Franconian noble family, traces its origins back to 1149 with a Gundeloh v. Blassenberg (Plassenberg). The name Guttenberg is derived from Guttenberg and was adopted by a Heinrich von Blassenberg around 1310. From 1340, the Hohenzollerns governed from Plassenburg castle their territories in Franconia till 1604. The Plassenburg was fortress and residence for the Hohenzollerns.

Casimir of Brandenburg-Bayreuth was Margrave of Bayreuth or Margrave of Brandenburg-Kulmbach from 1515 to 1527.