The canonization process of Pope Pius XII dates to shortly after his death in 1958. He was declared a Servant of God in 1990 and Venerable in 2009. Father Peter Gumpel is currently the relator of Pius XII's cause for canonization.
Archbishop van Lierde, archpriest of St Peter's Basilica and a close personal friend of Pope Pius XII, authorized and gave his Imprimatur to relic prayer cards in many languages dated December 8th 1958, two months less a day after the death of now Venerable Pope Pius XII. Most importantly, this authorized prayer released by the Vatican less than two months after Pope Pius XII' s death explicitly asks Our Lord, the Eternal Pontiff to hasten Pius being elevated to the Altars of the Church as a Saint. Officially mandated prayers for the canonization were thus current with official sanction weeks after the Pope's death. Certain claims that Monsignor Montini initiated the cause of canonization in the 1960s are not therefore supported by the facts clearly available to everyone.
Pope John Paul II declared Pius XII a Servant of God in 1990.
Pope Benedict XVI initially decided to postpone Pius XII's cause for sainthood upon his election in 2005. Benedict XVI had advocated waiting until the archives from Pius XII's papacy were opened to researchers in 2014. A selection, the ADSS, edited by a multinational team of Jesuits, was published between 1965 and 1981.
Benedict XVI changed his mind and declared Pius XII Venerable on December 19, 2009, based on the recommendation of the committee.Pope John Paul II, Benedict XVI's predecessor, was declared Venerable on the same day. The Congregation for the Causes of Saints certifies the "heroic virtues" of a candidate for Venerable status, although the final decision lies with the Pope. Benedict XVI was 12 years old when Pius XII was elected to the papacy in 1939; one Vatican insider described Benedict XVI's memory of Pius XII thus: "Pius is really his Pope."