Prince Karl Franz was born on 15 December 1916 in Potsdam. He was the only child born to Prince Joachim of Prussia by his wife Princess Marie-Auguste of Anhalt. Karl Franz was the Emperor's fourth grandchild to be born since World War I began; he was consequently very young when Hohenzollern fortunes fell. His grandfather abdicated in 1918, and his father Prince Joachim committed suicide in 1920. 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. As the legal head of the House of Hohenzollern, he claimed this right because Emperor Wilhelm had issued an edict placing Hohenzollern powers in Eitel's hands. This was later declared to have been illegal, and his mother was given full custody of him in 1921. She was given this right despite the fact that she had run away from her husband and that there had been numerous servants testifying against her. Eitel's defence had also stated that Marie-Auguste was not a fit person for Karl Franz's guardianship. Marie-Auguste went to court however and made a plea that she was heartbroken, which may have helped win the case for her. In 1922, Marie-Auguste sued ex-Emperor Wilhelm for financial support that had been promised in her and Joachim's marriage contract. Wilhelm's attorney argued that the House of Hohenzollern laws were no longer valid, and therefore there was no obligation to support her. In 1926, his mother remarried to Johannes-Michael, Baron von Loën. They were divorced in 1935. 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. He was awarded the Iron Cross.
Prince Franz Friedrich Christian of Prussia, firstly married in 1970 to Gudrun Winkler and had one daughter, Christine Prinzessin von Preussen, they later divorced in 1996. He secondly married in 1998 to Potsdam politician and former pianist Susann Genske, with no issue.
They divorced on 5 September 1946.
Second
Karl Franz married secondly, morganatically, on 9 November 1946, to Luise Dora Hartmann. The couple were childless and divorced in 1959.
Third
Prince Karl married lastly, on 20 July 1959 in Lima, PeruDoña Eva Maria Herrera y Valdeavellano. They were married until Prince Karl's death and had two daughters;
Alexandra Maria Augusta Juana Consuelo Prinzessin von Preussen. She married Dr. Alberto Reboa in 1995 in Hechingen, Germany. They have two children:
*Alberto Reboa y von Preussen
*Alexandra Reboa y von Preussen
Désirée Anastasia Maria Benedicta Prinzessin von Preussen. She married Juan Carlos Gamarra y Skeels on 25 May 1983 at Lima, Peru. They have two children: