The last independent Duke of Guelders was Adolf's son Charles of Egmond (1492-1538). He increased the size of the duchy northward, and included what is now the Province of Overijssel. He left the duchy to Duke William the Rich of Jülich-Cleves-Berg in his will. However, he was not able to hold on to it and Emperor Charles V of Habsburg soon moved in. Guelders finally lost its independence, when it was united with the Seventeen Provinces of the Habsburg Netherlands in 1543.