Munificentissimus Deus

Munificentissimus Deus (Latin: The most bountiful God) is the name of an Apostolic constitution written by Pope Pius XII. It defines ex cathedra the dogma of the Assumption of the Blessed Virgin Mary. It was the first ex-cathedra infallible statement since the official ruling on papal infallibility was made at the First Vatican Council (1869–1870). In 1854 Pope Pius IX made an infallible statement with Ineffabilis Deus on the Immaculate Conception of the Virgin Mary, which was a basis for this dogma. The decree was promulgated on 1 November 1950.

On 1 November 1950, invoking his dogmatic authority, Pope Pius XII defined the dogma:

Pope Pius XII's previous encyclical Deiparae Virginis Mariae (1 May 1946) to all Catholic bishops stated that for a long time past, numerous petitions had been received from cardinals, patriarchs, archbishops, bishops, priests, religious of both sexes, associations, universities and innumerable private persons, all begging that the bodily Assumption into heaven of the Blessed Virgin should be defined and proclaimed as a dogma of faith. This was also fervently requested by almost two hundred fathers in the Vatican Council (1869–1870).

Following the example of Pope Pius IX, who canvassed Catholic bishops before proclaiming the dogma of the Immaculate Conception, Pius XII asked all bishops for their opinion.

At issue was not the belief in the Assumption, but its dogmatisation. Munificentissimus Deus reports popular acclaim and "nearly unanimous" approval of the contemporary bishops. The names of the bishops attending the dogma celebration in 1950 are listed at the entrance of St. Peter's Basilica.

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