Wilhelm was born at Herleshausen, Hesse-Nassau, Germany, eldest child of Prince Wilhelm of Hesse-Philippsthal-Barchfeld (1905–1942), (son of Chlodwig, Landgrave of Hesse-Philippsthal-Barchfeld and Princess Caroline of Solms-Hohensolms-Lich) and his wife, Princess Marianne of Prussia (1913–1983), (daughter of Prince Friedrich Wilhelm of Prussia and Princess Agatha of Hohenlohe-Schillingsfürst).
The Wommen Viaduct is an arch bridge built between 1938 and 1940 near Wommen, Germany, as part of the Reichsautobahn system.