Congregation of Marian Fathers of the Immaculate Conception

The Congregation of Marian Fathers of the Immaculate Conception of the Most Blessed Virgin Mary (Latin: Congregatio Clericorum Marianorum ab Immaculata Conceptionis Beatissimae Virginis Mariae) is a Catholic male clerical religious congregation founded, 1670, in Poland. It is also known as Marians of the Immaculate Conception. Its members add the post-nominal letters M.I.C. after their names to indicate membership in the Congregation.

The Congregation of about 500 priests and brothers has convents in 19 countries on 6 continents. Marians pledge support to the Pope and follow the official teachings of the Catholic Church and aim to spread devotion to Blessed Virgin Mary as the Immaculate Conception, pray for the souls in purgatory and undertake a variety of apostolic work.

The Marians were the first Catholic religious institute for men dedicated to honor Mary’s Immaculate Conception. The community traces its roots to Stanislaus of Jesus and Mary Papczyński who was beatified in Basilica of Our Lady of Licheń, Licheń Stary, Poland, in 2007, and canonized on 5 June 2016 at Saint Peter's Square in Vatican City by Pope Francis. As an Institute of consecrated life, their motto is Pro Christo et Ecclesia.

They are also the official promoters of the Divine Mercy message since 1941.

On December 11, 1670, Stanislaus Papczyński publicly announced in his Oblatio the desire to establish a community of men dedicated to spreading the honor to the Immacuate Conception of the Blessed Virgin Mary. In 1673, in Puszcza Korabiewska (today known as Puszcza Marianska/Marian Forest) near Skierniewice, Poland, the first religious house of the Marians was approved by the local bishop. The first members of the community based their life on the Rule of Life, written by Papczyński. He tempered his plans at first to establish a community active in the church's service. At the beginning, the Marian Fathers lived an eremitical rule of life as they pursued final recognition and approval by the Catholic Church. Within a short time, the new and still small institute received approval from their local ordinary, Bishop Stephen Wierzbowski of Poznan.

Pope Innocent XII granted his approval for the young institute in 1699 with solemn vows under the French Rule of the Ten Virtues of the Blessed Virgin Mary, initially placing them within the Franciscans.

With the death of the founder in 1701, however, the Marian Fathers found themselves in a critical period of transition. Internal factions divided the membership into one group favoring a strictly contemplative life, and a second group seeking to add missionary and pastoral outreach to the institute's contemplative spirit. The period known as the "Rostkowski Dispersion" followed, fired by internal conflict, as well as the negative attitude expressed by some bishops and lay dignitaries. In 1716, Bishop Adam Rostkowski decided to close the Marian novitiate, instructing Marians to leave the monastery and move out to assume pastoral work in parishes.

In 1722, Bishop John Tarlo of Poznan called the scattered Marians back to their monasteries, and convened a general chapter. The man elected to serve as Superior General was Andrew of St. Matthew Deszpot, a Czech originally received into the institute by the founder Papczyński. At the same chapter, a general procurator was chosen, Joachim of St. Ann Kozłowski. He was given the mission of going to Rome to have the institute's constitutions confirmed, and to remove the institute from the jurisdiction of local bishops. In 1723, Pope Innocent XIII approved the Marian statutes and released the institute from the interference of local bishops.