While the Brandenburg electorate became the power base for the rising Hohenzollern dynasty, the Principality of Kulmbach-Bayreuth was held by Frederick's descendants, temporarily in personal union with Ansbach.
The rulers were commonly known as the Margraves of Brandenburg-Bayreuth (though Bayreuth is nowhere near Brandenburg).
Kulmbach-Bayreuth became part of the Franconian Circle in 1500.

After in 1541 the ambitious Margrave Albert Alcibiades assumed the rule over Kulmbach-Bayreuth, he barged onto the battlegrounds of the Schmalkaldic War, several times switching sides between Emperor Charles V and the Lutheran princes of the Schmalkaldic League.
In 1552 he sparked the Second Margrave War against Nuremberg and the neighbouring Prince-bishoprics of Würzburg and Bamberg.
His soaring plans to re-establish the medieval Duchy of Franconia under his rule ended with his utter defeat and an Imperial ban in 1554.

Albert was succeeded by his cousin Margrave George Frederick in 1557, who from 1577 als ruled in the Duchy of Prussia as regent for his incapable Hohenzollern relative Duke Albert Frederick, Duke of Prussia.
With George Frederick's death in 1603, the elder Bayreuth line became extinct.
He left his successor, Margrave Christian, younger son of the Brandenburg elector John George, an orderly and functioning state.
While the Brandenburg electorate became the power base for the rising Hohenzollern dynasty, the Principality of Kulmbach-Bayreuth was held by Frederick's descendants, temporarily in personal union with Ansbach. The rulers were commonly known as the Margraves of Brandenburg-Bayreuth (though Bayreuth is nowhere near Brandenburg). Kulmbach-Bayreuth became part of the Franconian Circle in 1500.
After in 1541 the ambitious Margrave Albert Alcibiades assumed the rule over Kulmbach-Bayreuth, he barged onto the battlegrounds of the Schmalkaldic War, several times switching sides between Emperor Charles V and the Lutheran princes of the Schmalkaldic League. In 1552 he sparked the Second Margrave War against Nuremberg and the neighbouring Prince-bishoprics of Würzburg and Bamberg. His soaring plans to re-establish the medieval Duchy of Franconia under his rule ended with his utter defeat and an Imperial ban in 1554.
Albert was succeeded by his cousin Margrave George Frederick in 1557, who from 1577 als ruled in the Duchy of Prussia as regent for his incapable Hohenzollern relative Duke Albert Frederick, Duke of Prussia. With George Frederick's death in 1603, the elder Bayreuth line became extinct. He left his successor, Margrave Christian, younger son of the Brandenburg elector John George, an orderly and functioning state.
Principality of Bayreuth