Stanislaus Papczyński was born on 18 May 1631 at Podegrodzie, Poland, in times of great upheaval. He was a lively, enterprising boy who tended his father's sheep with care. Initially, he had difficulty with his studies but diligently persevered. He graduated from both Piarist and Jesuit Colleges. His parents had hoped he would marry, but he announced his intention to dedicate himself totally to the service of God.

On 2 July 1654 he entered the Piarist Order founded by Fr Joseph Calasanctius in 1597 (also known as The Order of Poor Clerics Regular of the Mother of God of the Pious Schools [Sch. P]) and took the religious name of Stanislaus of Jesus-Mary. He made his religious profession on 22 July 1656 and was ordained a priest on 12 March 1661.

While still a seminarian he taught rhetoric using a textbook that he wrote, "The Messenger of the Queen of Arts", for which he received great praise.

Fr Stanislaus was also valued as a confessor and for his sermons to the intellectual elite. Due to his influential contacts, his Order requested that he seek support for Fr Calasanctius' cause to raise him to the honour of the altars.

Despite his academic and pastoral success, Fr Papczyński experienced an uneasy period concerning his vocation. He called this time "a lengthy martyrdom" which he spent in frequent meditation on the Passion of Christ.

Fr Papczyński requested an indult in 1669 and at that time made an oath in the presence of his Piarist Superiors: "I offer and consecrate to God... as well as to the Mother of God, the ever-Virgin Mary conceived without sin, my heart, my soul and my body, leaving absolutely nothing for myself.... I vow to serve them zealously, in chastity, to the end of my life, in the Society of Marian Clerks of the Immaculate Conception, which by the grace of God I wish to found".

Until that time all religious Orders in Poland had been founded abroad, so it was doubtful that a commoner like Fr Stanislaus would find approval for this new Society. But his trust in God was rewarded with support for his plan from the Bishop of Poznan, Poland.

In September 1671 he took the white habit in honour of the Immaculate Conception and prepared the future Order's Statutes or "Rule of Life".

Two years later, near Skierniewice, he founded the Institute's first house, which he called a "Retreat House", with a small group of hermit companions. On 24 October 1673, when the local Bishop made a canonical visitation, their "Rule of Life" was approved. The Marians consider this date as the beginning of their Order.

On 21 April 1679 the Institute became an Order of Diocesan Right and worked to spread devotion to the Immaculate Mother of God and to assist souls in Purgatory, especially those who were unprepared for death. This apostolate responded to Poland's needs, sorely tried by wars and the plague.

Eventually, the hermitical lifestyle became more apostolic with emphasis on teaching the truths of the faith. Fr Papczyński also stressed the importance of preaching and pastoral care in the Sacrament of Confession. To address the vice of drunkenness he imposed abstinence from vodka on his Order.

In 1690, wishing to entrust the Order to the Holy See, the Founder set out on foot at the age of 60 to seek Papal approval in Rome. Upon his arrival Fr Stanislaus discovered that the Holy See was sede vacante; consequently, he compensated by establishing a "spiritual affiliation" of the Marians with several other Orders.

In 1699, too elderly to make the journey, Fr Stanislaus again sought Papal approval by sending to Rome his confrere, Fr Joachim Kozlowski, as his delegate. Fr Kozlowski approached the reformed Franciscan Minors in Rome for the "Rule of Ten Virtues of the Blessed Virgin Mary", which included the Marians' legal dependence on this Order.

Pope Innocent XII approved the document presented by the General of the Franciscans in 1699: the Marians became an Order with solemn vows, although they remained dependent on the Franciscans for some time.

After more than 30 years of foundation, Fr Papczyński pronounced his solemn vows on 6 June 1701 and then received the profession of the other Marians. The result: the first Polish Order of Apostolic Right of male religious in Poland's history.

Having completed the work God entrusted to him, Fr Papczyński died just a few months later on 17 September 1701 in Gora Kalwaria, Poland.

On 13 June 1992 Pope John Paul II declared him Venerable.