Simplify the following text for a Grade 6 native English-speaking person.
Original: He bequested the duchy to Duke William the Rich of JÃ 1\/4 lich-Cleves-Berg , who however was not able to hold on to it and Emperor Charles V of Habsburg soon moved in .
Simplified: He left the duchy to Duke William the Rich of JÃ 1\/4 lich-Cleves-Berg in his will . However , he was not able to hold on to it and Emperor Charles V of Habsburg soon moved in .