In 1609 John William, Duke of Jülich-Cleves-Berg, died childless and the Elector of Brandenburg lays claim to inheritance.
Kurfürst Johann Sigismund von Brandenburg erhebt Erbansprüche auf Jülich-Kleve-Berg
John William, Duke of Jülich-Cleves-Berg (1562-1609), dies childless in March 1609. It is an open issue as to who should assume authority in the three duchies and the County of Mark. The Lower Rhine became a zone of conflict and area of primary interest for the major powers due to the conflict between the Dutch provinces and the Spanish crown.
Various parties lay claim to the inheritance. The circle of possible inheritors also includes Duke John William's niece Anna of Prussia (1576-1625), married since 1594 to John Sigismund, Elector of Brandenburg (1572-1620). Around two weeks after the death of John William they suddenly seize the estate on 4 April 1609.