Catherine Sophie Helene "Sophie" (Hartung) Vassel was born in Berlin, Germany. Her family originally came from Bad Langensalza, and they returned to Schwarzburg, Schwarzburg-Rudolstadt, Thüringen for vacations. Günter Victor Prince of Schwarzburg-Rudolstadt was married to Princess Anna Louise of Schönburg-Waldenburg (1871–1951)in 1891. Catherine Sophie Helene (Hartung) Vassel became the friend and lady-in-waiting to Princess Anna Louise at the castle in Schwarzburg. Sophie's grandson, Bruno Vassel II, remembered visiting the castle with his grandmother when he was about 8 years old in about 1916. Sophie and her husband Gustav Leon Alfred Vassel moved from Berlin to Schwarzburg in 1897. Their son Peter started a private boy's school in Schwarzburg in 1919 which was a successful international school for boys until 1938 when it was taken over by the Nazi government. The property is now a forestry school. Sophie lived in Schwarzburg until her death in 1942. She had four children, Philipp b. 1873, twins Elfriede and Bruno I b. 1875 and Peter b. 1878.