Marian years are decided on and declared exclusively by the Pontiff of the Roman Catholic Church. In Church history, only two Marian years were pronounced by Pope Pius XII and Pope John Paul II.
In 1953, with the encyclical Fulgens corona, Pope Pius ordered a Marian year for 1954, the first in Church history. The year was filled with Marian initiatives, in the areas of Mariology, cultural events, and charity and social gatherings.
The Pope promotes appropriate sermons and discourses to explain Marian beliefs. The purpose is to increase the Faith of the people and their devotion to the Virgin Mother. Marian churches and Marian shrines all over the world, "or at least an altar, in which the sacred image of the Blessed Virgin Mary is enshrined" should invite to public services for the devotion of the Christian people. The Pope invites especially to celebrations at the Grotto of Lourdes, "where there is such ardent devotion to the Blessed Virgin Mary conceived without stain of sin".
In 1987, Pope John Paul II initiated a Marian year in preparation of the forthcoming millennium. He published the encyclopedic Marian encyclical Redemptoris Mater, which constitutes the longest Marian encyclical ever written by a Pontiff. It represents the status of Marian belief and Mariology for the beginning of the 21st century. For the beginning of the Marian year, a large copy of the Madonna della Colonna was completed for outside Saint Peter's Square. Pope John Paul II had been approached by a student who told him that Saint Peter's Square was cold and incomplete without the portrait of the Blessed Virgin Mary. In both Marian years, Marian devotion, Marian pilgrimages and Marian meetings were promulgated.