 Konrad, his great-grandfather, started a Silesian cement business in the late 19th century; the town square in Groszowice is named after him.von Prondzynski's grandfather, Alfred, was a lieutenant in the First World War, in which he was seriously wounded; he died later from his wounds, in 1932.His grandmother later remarried in the 1930s to a retired admiral, Karl Feldmann (who worked for the Ministry of Labour) when Ferdinand's father, Hans, was still a young man.