Background
His parents were William the Rich, Duke of Jülich-Cleves-Berg (1516-1592) and Maria of Austria (1531-1581), a daughter of Ferdinand I, Holy Roman Emperor and Anna of Bohemia and Hungary. He grew up and was educated in Xanten.
His parents were William the Rich, Duke of Jülich-Cleves-Berg (1516-1592) and Maria of Austria (1531-1581), a daughter of Ferdinand I, Holy Roman Emperor and Anna of Bohemia and Hungary. He grew up and was educated in Xanten.
Johann Wilhelm became Bishop of Münster. He was also Count of Altena. The United Duchies of Jülich-Cleves-Berg was a combination of reichsfrei states within the Holy Roman Empire.
Johann Wilhelm was first married in 1585 to Jakobea of Baden (d 1597), daughter of Philibert, Margrave of Baden.
He was secondly married to Antonia of Lorraine (d 1610), daughter of Charles III, Duke of Lorraine. He was subject to mental illness, for which he was treated by the physician Francesco Maria Guazzo.
Ultimately, Brandenburg received Cleves-Mark and Neuburg received Jülich-Berg, after the lands had been trampled under military several times and lost much of the fabled wealth so renowned in Duke Wilhelm"s time. Among his court servants and employees were the composer Konrad Hagius.