[2] The outbreak of the Second World War deprived Karl of his father, who enlisted in the German army in the first months of the conflict[3] and who disappeared in an air accident in 1943.

[5] Orphaned by his father at an early age, Karl was later adopted by one of his paternal uncles, Prince Wolfgang of Hesse, in 1952.

In 1960, Karl was invited to Stockholm on the occasion of a grand ball organized in honor of the granddaughters of King Gustaf VI Adolf of Sweden.

[7] Two children were born from this marriage: While he was established in Munich with his wife, Karl was known for his interest in oriental philosophies and alternative medicines.

[9] Karl briefly discussed his mother's childhood and her ties to the Nazi regime in a documentary in 2015 about his uncle, Prince Philip: The Plot to Make a King (2015).