It was founded in 1921, in Dublin.
Membership is open to men and women, married or single, to boys and girls.
The legion draws it inspiration from the realisation of the immense intercessory power of Our Lady with her Divine Son, and from the conviction that she is the divinely appointed Mediatrix of all Graces. In 1955, the first praesidium was founded in Sandakan. Our praesidium has now attained its 43rd year and is growing strong. Four more praesidium in Chinese were added in the last 10 years. The main aim is to spread and make known our Lord Jesus and love through Mary, His mother.