The death without direct heirs of Duke John William in 1609 led to serious complications in which almost all the states of Europe were concerned; however, by the treaty of Xanten in 1614, Cleves passed to the elector of Brandenburg, being afterwards incorporated with the electorate by the great elector, Frederick William.
Even the great fortress of Castra Vetera (Xanten) was starved.
Later, the pagus Attuariorum corresponds to the district of Emmerich and Xanten.
Otto gained a victory near Xanten, which was followed by the surrender of the fortresses held by his brother's adherents in Saxony, but the rebels, joined by Eberhard of Franconia and Archbishop Frederick of Mainz continued the struggle, and Giselbert of Lorraine transferred his allegiance to Louis IV., king of France.
A standing army was kept up on the Rhine, divided into two commands, upper and lower Germany, the headquarters of the former being at Mainz, those of the latter at Vetera, near Xanten.