 Eugen's older sister was Princess Amalie Isabella of Bavaria, born 1921.On 16 November 1970, Prince Eugen married Countess Helene of Khevenhüller-Metsch (4 April 1921 in Vienna – 25 December 2017 in Bad Hindelang), daughter of Count Franz of Khevenhüller-Metsch and Princess Anna of Fürstenberg.Countess Helene was previously married to Prince Konstantin of Bavaria, who lost his life in a plane crash on 30 July 1969.