Frank Duff was born in Dublin, Ireland, on 7th June 1889, the eldest of seven children.

In 1913 he joined the Society of St Vincent de Paul and was greatly influenced by the spirit of the society. As a member, he gradually came to have a great love for the poor and underprivileged in whom, as in everybody he met, he recognised and honoured Christ.

In 1916 , aged 27, he published his first pamphlet, “Can we be Saints ?”. In it he expressed one of the strongest convictions of his life, namely, that all withoout exception are called to be sainsts and that through our Catholic faith, we have available all the means necessary to attain this.

In 1917 he came to know the Treatise of St Louis Marie de Montfort on the True Devotion to Mary, a work which chamged his life completely.

On September 7th 1921 Frank Duff founded the Legion of Mary, a lay apolostic organisation at the service of the Church, under ecclesiastical guidance. Its twofold purpose is the spiritual development of its members and advancing the reign of Christ through Our Lady.

The Legion, which is found in almost every country in the world, has nealry 3 million active members and many more auxiliary (praying) members.

In 1965 Pope Paul VI invited Frank Duff to attend the Second Vatican Council as a Lay Observer, an honour by which the Pope recognised and affirmed his enormous work for the lay apostolate.

In July 1996 the Cause of his canonisation was introduced by the Archbishop of Dublin, Dr Desmond Connell.