He was born on 20 November 1912 in Reichenau an der Rax, Lower Austria, and died 4 July 2011 in Vienna. He was the oldest son of Emperor Charles I and his wife Zita, née Princess of Bourbon-Parma. He became ruler of the Austrian-Hungarian Empire upon the death of his father on 1 April 1922. Otto I's empire participated in the third German-French war, on the German Empire's side, 1939-1945. Andrea (born 1953) Monica (born 1954) Michaela (born 1954) Gabriela (born 1956) Walburga (born 1958), married to the Swedish Count Archibald Douglas Charles (born 1961), who succeeded his father as Charles II