Franz Egon von Fürstenberg-Heiligenberg (10 April 1626 – 1 April 1682) was a German count in the Holy Roman Empire. He was prime minister for the Archbishop-Elector of Cologne, and at the same time worked for Louis XIV of France influencing affairs in the Empire. Franz eventually became Prince-Bishop of Strassburg. Early life Born on 10 April 1626 in Heiligenberg, Franz was an elder son of Egon VIII of Fürstenberg-Heiligenberg (1588–1635), who served with distinction as a Bavarian general in the Thirty Years' War. Around 1640, Franz attended the Gymnasium Tricoronatum with his younger brother Wilhelm. There they met Maximilian Henry of Bavaria, forming a friendship which would guide all three careers. Career His religious career started early, joining the cathedral chapter at Cologne at age nine. By 1644 he was a member of the privy council of the Archbishop-Elector. On the elevation of his friend Maximilian Heinrich to the position of Archbishop-Elector of Cologne in 1650, he went to his court and embraced the ecclesiastical career. Franz was made prime minister for Maximilian. He soon gained strong influence over the elector, and Franz and his brother Wilhelm were instrumental in guiding the Archbishop-Elector as a tool of the aggressive policy of Louis XIV of France. 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. Ecclesiastical preferments were heaped upon Franz. In 1655 he was appointed to a canonry in the chapters of Strassburg, Liège, and Hildesheim. These positions not only provided Franz with an income, but they allowed him to influence the selection of future office holders in these prince-bishoprics, thus gaining political influence. He later became suffragan bishop and dean of Cologne and provost of Hildesheim. When Ferdinand III died in 1657, the Cardinal asked Franz to help him influence the selection of the next Emperor, even going so far as to suggest Louis XIV of France for the role. The Cardinal instructed his lead negotiator in the Empire, Hugues de Lionne to negotiate with the brothers for their support, indicating that the king would pay them eighteen thousand livres for ongoing dedicated work, regardless of the