Immediately following the Normandy landings in June 1944, the king, his new wife Lilian, Princess of Réthy, whom he had married in September 1941, and the royal children, were deported to Hirschstein in Germany and then to Strobl in Austria from where they were liberated in May 1945 by the United States Army. However, the royal family were prevented from returning to Belgium by the "Royal Question" over whether Leopold had collaborated with the Nazis; the surrender in 1940, his refusal to join the government-in-exile, his fruitless visit to Adolf Hitler at the Berghof in November 1940 and his unconstitutional marriage to Lilian whose father was believed to be pro-Nazi. Until a political solution could be found, the king's brother, Prince Charles became regent and the royal family lived at the Château du Reposoir in Pregny-Chambésy, Switzerland. Baudouin continued his education at a secondary school in Geneva and visited the United States in 1948. In a referendum in March 1950, the public narrowly voted for the king to return and he was recalled on 4 June 1950. However, parliamentary dissent and public protests forced Leopold to delegate his powers to Baudouin on 11 August 1950, and finally to abdicate in favour of Baudouin, who took the oath of office as the fifth King of the Belgians on 17 July 1951.