In March 1944 Mindszenty was named bishop of Veszprém. He opposed the German occupation of Hungary during World War II and was imprisoned in November 1944. Released in April 1945, he became the archbishop of Esztergom later that year and was elevated to cardinal in 1946.
Mindszenty openly opposed the policies, especially the seizure of church lands and properties, of Mátyás Rákosi, Hungary's deputy prime minister and general secretary of the Hungarian Communist Party. Mindszenty also publicly denounced the secularization campaign and rigged elections of 1947. Arrested on 26 December 1948 and accused of treason, he was subjected to five weeks of torture, whereupon he confessed to the charges against him and was tried and subsequently condemned to life imprisonment.
Mindszenty's 1949 trial and imprisonment caused international indignation. Pope Pius XII raised his own objections, and the United Nations (UN) General Assembly declared it an international crime. In spite of persecution, however, Mindszenty remained committed to the Church and to Christian values. In 1955, because of ill health, he was transported to Felsőpetény, where he was kept under house arrest.
Mindszenty's release was among the demands of the prodemocracy forces during the 1956 Hungarian Revolution. He was set free on 31 October 1956. On 3 November he gave a radio speech in which he criticized Soviet-style land reform and economic policies. On 4 November, warned about Soviet tanks advancing on Budapest, he sought and secured refuge at the U.S. legation in Budapest. He lived in its compound until 1971. In 1962 he was tried in absentia for his role in the 1956 revolution and found guilty of treason.
Following drawn-out negotiations among Washington, the Vatican, and Hungarian officials, on 28 September 1971 Mindszenty was allowed to leave Hungary and settled in Vienna. During his last years, he took on an international role and embarked on missions around the world, also visiting Hungarian enclaves around the globe. Because Mindszenty opposed relations between the Vatican and Hungary, Pope Paul VI requested his resignation as primate in 1973. But Mindszenty refused to resign, believing that such a step would only reward the communist regime for its deplorable behavior.
Cardinal Mindszenty died in Vienna on 6 May 1975. In 1994, Pope John Paul II began the canonization process for him.
Mindszenty, József. Memoirs. London: Weidenfeld and Nicolson, 1974.; Swift, Stephen K. The Cardinal's Story: The Life and Work of Cardinal Mindszenty, Archbishop of Esztergom, Primate of Hungary. New York: Macmillan, 1949.