Frank Duff is most likely the greatest Irishman of the 20th century. He was chosen by Our Lady to found an army with global reach. This happened in 1921 a few years after the most important apparition of Our Lady in Fatima, Portugal. The legacy of this lay Apostolate is huge with branches of the Legion on every continent of the world. It is the largest lay Apostolate in the Catholic Church.
The objective of the Legion is the personal santification of its members through a combination of prayers and evangelising work within the Parish to which it is attached.