Frederick VII of Denmark
Karl married Princess Vilhelmine Marie of Denmark, daughter of Frederick VI of Denmark and his wife Marie Sophie of Hesse-Kassel, on 19 May 1838 at Amalienborg Palace in Copenhagen, Denmark. Vilhelmine Marie was the former wife of Prince Frederick of Denmark (later Frederick VII of Denmark). He died on 24 October 1878 at age 65 at Luisenlund. Karl and Vilhelmine Marie died without issue. Many believe that she was barren as there are no records of her having any miscarriages or stillbirths.