Ka cika wannan jumla: A lokacin Yaƙin Shekaru Tara, Prospero ya taimaka sosai a yaƙin da William III na Orange ya yi a shekara ta 1691 da ƙasar
Faransawa sun kewaye Mons. A cikin 1695, ya jagoranci kewaye da Namur tare da injiniyan soja na Dutch Menno van Coehoorn. An ci gaba da shi zuwa filin marshal na dakarun dakarun Mutanen Espanya kuma, bayan shekaru biyu, ya umurci Lorraine Regiment of Cavalry.