Johann Georg von Brandenburg

Born at Wolmirstedt, Johann Georg was the second son of Elector Joachim Friedrich of Brandenburg and Katharina von Brandenburg-Küstrin.

The Emperor Rudolf II, in whose Kingdom of Bohemia the Duchy of Jägerndorf lay, refused to admit Johann as duke and asked for Beuthen and Oderberg as pledges.

When the Thirty Years' War broke out in 1618, the Silesian estates joined the Bohemian in opposing the Emperor Ferdinand II.

Although Johann played a relatively minor role in the military actions of the first few years, he was the only Silesian or Bohemian nobleman deposed by the victorious Ferdinand after the Battle of the White Mountain (29 January 1621).

He joined with the Transylvanian prince Gabriel Bethlen, elected King of Hungary in opposition to Ferdinand, and was instrumental in his military success in 1621.