[1] At the time of his grandfather's abdication, Prince Karl Franz was twelfth in line of succession to the German and Prussian thrones.

After his father's suicide, Karl Franz was taken into custody by his paternal uncle, Prince Eitel Friedrich of Prussia.

[4] In 1922, Marie-Auguste sued ex-Emperor Wilhelm for financial support that had been promised in her and Joachim's marriage contract.

In World War II, Karl Franz served as a lieutenant in an armoured car division, and at one point was stationed on the Polish front.

On 1 October 1940, Karl Franz married Princess Henriette Hermine Wanda Ida Luise of Schönaich-Carolath.