 John Cicero was the eldest son of Elector Albert III Achilles of Brandenburg with his first wife Margaret of Baden.As his father then ruled as Margrave of Brandenburg-Ansbach (from 1457 also as Margrave of Brandenburg-Kulmbach), he was born at the Hohenzollern residence of Ansbach in Franconia, where he spent his childhood years until in 1466 he received the call to Brandenburg as presumed heir by his uncle Elector Frederick II.He joined him in the War of the Succession of Stettin with the Pomeranian dukes, until Frederick resigned in 1470 and was succeeded by John's father, who in 1473 appointed him regent of the Brandenburg lands.