In 1939, as most young German men of his age, the Prince was drafted to the military. However, his career in the German Army was short lived. In 1941, Prince Konstantin was relieved from all combat duties as a result of the so called "Prinzenerlass" and a year later started studying law at Albert-Ludwigs-Universität in Freiburg im Breisgau. After his graduation in 1944, he worked at the Higher Regional Court of Karlsruhe, but was arrested, as were most of his relatives, after the failed attempt to assassinate Adolf Hitler and remained imprisoned for the rest of World War II.