Consecration of Russia

The Consecration of Russia to the Immaculate Heart of Mary by a specific act of a Pope along with all the other Catholic bishops of the world was ordered by Our Lady of Fátima in 1917.

The controversial belief is associated with the Marian apparitions in Cova da Iria, at Fátima, Portugal, to three Portuguese children in 1917 and later to the one survivor of the three, Lúcia Santos at the city of Tuy, Spain in 1929, in which Sister Lúcia reported a vision representing God the Father, the Holy Spirit and Jesus. Lúcia stated that at different times the Virgin Mary had given her messages that emphasized praying the Rosary, and that she had made a number of prophecies and promises, one of these being that the consecration of Russia would usher in a period of world peace.

In response, Pope Pius XII (1942), Pope John Paul II (1984), Pope Benedict XVI (2010) and Pope Francis (2013) consecrated the world to the Immaculate Heart, with Pius XII also specifically consecrating "the peoples of Russia" in 1952, sometimes worded as "acts of entrustment".

Though Sister Lúcia Santos publicly declared that the consecrations of both 1942 and 1984 were accepted in Heaven, certain pious devotees to the cause of Fátima, especially Traditionalist Catholics, dispute that a valid consecration of Russia, fulfilling the specific requirements of the Marian apparition at Tuy that were carried out since the consecration has never been performed in union with all the Catholic bishops of the world as was requested, nor that the specific mandate "Consecration of Russia" is expressed in wording verbatim by the reigning Pope. The controversial topic remains to be an issue of disagreement stemming from the ecclesial changes ushered by the Second Vatican Council.

...
Wikipedia