Confraternities and archconfraternities
Legion of Mary
Legio Mariae · The Legion · Concilium Legionis Mariae (central council)
St Louis Marie de Montfort whose True Devotion shapes it
Founded 1921International lay apostolic association of the faithful, under the patronage of Mary Immaculate, Mediatrix of All Graces; requires ecclesiastical approval to operate in a diocese or parish; central council (Concilium) in DublinOver 10 million active and auxiliary members worldwide in about 170 countries; commonly described as the largest apostolic organization of lay people in the Catholic Church
A few minutes' work
Through a local group. Free; voluntary secret collection is taken at meetings and the Handbook and Tessera are purchased.
How to find or start oneCall or visit your own parish office, ask for the weekly meeting time of the praesidium, and turn up; new members are accepted at any time of year.
Members have a portal to sign in to.
The Legion of Mary is the most straightforward of all these groups to join and the most demanding week to week. The local unit, called a praesidium, meets every single week, and at that meeting prayer is mixed with members reporting on the apostolic work they were assigned the week before. You are then given a new task and you go out, almost always in pairs, to do it: visiting families door to door, visiting the sick in homes and hospitals, reaching out to Catholics who have drifted away, or helping with whatever the parish is doing. There is a second grade of membership, called auxiliary, for people who cannot do the active work but who commit to praying the Legion's daily prayers. People join because it turns vague good intentions into a specific weekly assignment with someone expecting a report.
What you promise
Apply for membership in a praesidium. Active members attend the weekly praesidium meeting, carry out a weekly apostolic work in pairs, and pray the Catena daily. After a successful probation period, members aged 18 and over are called to make the Legionary Promise, which is directed to the Holy Spirit. Auxiliary members have no meeting attendance requirement at all and simply pray the full Tessera (the Legion's prayer card) daily.
What the Church attaches
Formation in the apostolate and in True Devotion to Mary as taught by St. Louis Marie de Montfort, with priests and religious serving as Legion Spiritual Directors. Daily union in prayer with every legionary worldwide through the Tessera. A genuinely low-barrier auxiliary option for people who cannot commit to active service.
Before full membership
a probation period before making the Legionary Promise; no fixed multi-year term is published
Enrollment checked 2026-10-22. Details change without notice and parish practice varies. Confirm before relying on this sheet.