Simplify the following text for a Grade 9 native English-speaking person.
Original: In 1709 , when his health had already deteriorated , he obtained the Papal dispensation from the cardinalate , and was forced to marry Eleonora Luisa Gonzaga , daughter of Vincenzo Gonzaga , Duke of Guastalla , in an attempt to save the dynasty .
Simplified: In 1709 , even though in bad health , he was forced to marry Eleonora Luisa Gonzaga after a plan for him to marry the French Charlotte of Lorraine had failed at the instigation of Louis XIV . Gonzaga was a daughter of Vincenzo Gonzaga , Duke of Guastalla , to try and save the dynasty .