In 1663, the joined the Venetian army and fought in the Turkish War. A year later, he fought in the battle of St. Gotthard. In 1665, he laid down his arms, entered the Benedictine Rheinau Abbey and received minor orders. In 1666, he was appointed coadjutor of the prince-bishop of Fulda. In 1668, he also became coadjutor of Kempten Abbey. In 1671, he became Prince-Bishop in Fulda and coadjutor in the Michaelsberg Abbey in Siegburg.