Career
He was elected the successor of the then 86-year-old Archbishop Philipp Christoph von Sötern, but this was rejected as Philipp Christoph was the favoured candidate. After the death of the Archbishop, Karl Kaspar started his reign on 12 March 1652. The consequences of the recently ended Thirty Years" War presented the new archbishop with many hard tasks, for example, the population of the archiepiscopal state had declined to approximately 300,000 people.
His policy towards the Allies had destroyed many buildings.
So he had to restore the country’s infrastructure, especially the justice and agriculture systems, to promote development. He also had to repair the fortresses Koblenz and Ehrenbreitstein.
He founded an orphanage for boys in Trier and endowed scholarships for the training of nobles’ sons to become priests, and in 1668, he had the Kurtrierische Landrecht ("Electoral-Trier Common Law") published. He died on 1 June 1676 in Fort Ehrenbreitstein.