Georg Friedrich reigned in Ansbach and Jaegerndorf since 1556 and after the death of his cousin Alcibiades in 1557 also in Bayreuth.
He took over the administration of Ducal Prussia in 1577, when the then-reigning duke (Albert Frederick) became ill.
He was the last of the older Frankish line of the House of Hohenzollern. Upon his death in 1603 Ansbach and Bayreuth were inherited according to the Gera house treaty of 1598 by younger princes of the Brandenburg line.