Wilhelm Egon von Fürstenberg-Heiligenberg (2 December 162910 April 1704) was a German count and later prince of Fürstenberg-Heiligenberg in the Holy Roman Empire. He was a clergyman who became bishop of Strasbourg, and was heavily involved in European politics after the Thirty Years' War. He worked for the Archbishop-Elector of Cologne and Louis XIV of France at the same time, and was arrested and tried for treason for convincing the Elector to fight on the opposite side of a war from the Empire. Early life Wilhelm was a younger son of Egon VIII of Fürstenberg-Heiligenberg and Anna Maria of Hohenzollern-Hechingen. His father died in the Thirty Years' War in 1635, when Wilhelm was young. Starting in 1637, Wilhelm attended the Gymnasium Tricoronatum with his elder brother, Franz Egon. There they met Maximilian Heinrich of Bavaria and formed friendships that would shape all their careers. Wilhelm then went on to study in Louvain in 1643, and after that to study theology in Rome in 1646. While there, he was presented to Pope Innocent X and made a favourable impression. Career In 1648, Wilhelm was made subdeacon in the cathedral chapter at Cologne, and the following year joined Franz as a member of the Archbishop-Elector's privy council. In 1650, when their friend Maximilian inherited the role of Archbishop-Elector, Wilhelm and Franz gained significant influence in the court. In 1651, Cardinal Mazarin stayed in Cologne as a safe haven during the Fronde. During that time, he got to know Franz and Wilhelm, and to see the influence they had in Cologne and other lands within the Empire. He began to cultivate them as supporters of French aims within the Empire, supporting their interest in developing Rhineland defensive alliances. In 1656, the Cardinal gave Wilhelm control of the Abbey of St. Michel en Thiérache near Soissons. Impact in the empire When Ferdinand III, Holy Roman Emperor, died in 1657, Mazarin asked Wilhelm to help him influence the selection of the next Emperor, even going so far as to suggest Louis XIV of France for the role. Maximilian and the Electors of Mainz and Trier sent Wilhelm to Ferdinand Maria, Elector of Bavaria, to see if he would be willing to be put forth as the next Emperor, but he declined. Wilhelm also reported this result in person to the Cardinal and Louis XIV, and let them know that the French king did not have