For many years, Walther Franz was devoted to a military career. He participated in many successful battles under the leadership of one of the greatest generals of that time, Prince Eugene of Savoy. In 1697 he fought against the Turks in the Battle of Zenta, during 1704-1706 he participated in the War of the Spanish Succession against the French in the Battles of Blenheim and Turin. In 1717 he participated in the siege and conquest of Belgrade.