John I of Brandenburg-Küstrin left a fortune of more than half a million guilders, while his brother left behind debts of 2.5 million guilders. Marriage and issue John married on 11 November 1537 in Wolfenbüttel, Duchess Catherine of Brunswick-Wolfenbüttel (1518–1574). From this marriage, he had two daughters: Elisabeth (1540–1578)
- 13 January 1571 (aged 57)
- Catherine of Brunswick-Wolfenbüttel
John, (born Aug. 3, 1513, Tangermünde, Brandenburg—died Jan. 13, 1571, Küstrin, Neumark, Brandenburg), margrave of Brandenburg-Küstrin and a German Protestant ruler who remained loyal to the Catholic Habsburg emperors; he fought against his fellow Protestant princes and was conspicuously successful in the government of his territories.
Cuando Joachim I murió el 11 de julio de 1535, se creó para John el Margraviato de Brandenburg-Küstrin; consistía en los territorios de la Nueva Marcha con Dramburg y Schivelbein, la Tierra de Sternberg, Crossen an der Oder con Züllichau y Sommerfeld y la Loardship de Cottbus con Peitz, en total unos 12.500 kilómetros cuadrados.
John I of Brandenburg-Küstrin left a fortune of more than half a million guilders, while his brother left behind debts of 2.5 million guilders. Marriage and issue John married on 11 November 1537 in Wolfenbüttel, Catherine of Brunswick-Wolfenbüttel (1518–1574).
John fell out of favour; he was not arrested, due to the intercession of King Ferdinand (the later Emperor Ferdinand I and also because his brother Joachim was an Elector. After he returned to his Margraviate of Brandenburg-Küstrin, John strengthened its defenses and started planning an anti-Habsburg alliance, which however did not come about.
John, Margrave of Brandenburg-Küstrin 1513 1571 John, Margrave of Brandenburg-Küstrin in Biographical Summaries of Notable People John, Margrave of Brandenburg-Küstrin was born on August 3 1513, to Joachim I Nestor, Elector of Brandenburg and Elizabeth of Denmark, Electress of Brandenburg .