The EYM, as we know it, is the result of a vast evolution whose roots go back to a training house of the Society of Jesus, at Vals, near Le Puy in France. On December 3rd 1844, the feast of Saint Francis Xavier, the spiritual Father Francis Xavier Gautrelet made the famous exhortation from which the Apostleship of Prayer (AP) was born. Wishing to satisfy his young brothers' impatience to go on missions in distant lands, he exhorted them to be missionaries "right now", during their studies, through prayer and the daily offering of their lives, in union with Jesus Christ in the Eucharist.

In 1865 the spiritual Father of the Tivoli College of Bordeaux, Leonardo Cros, instituted the "Pope's Militia". It was the year in which Pius IX, threatened by Garibaldi's troupes, called on Catholic adults and young men to come to his help. This was the time when the epic of the pontifical zouaves started. Many students were eager to enrol. And history repeated itself: to calm their impatience Father Cros followed Father Gautrelet's idea and explained to the young people that they could be the Pope's zouaves in their own way, with their prayers, hours of silence, sacrifices and communions. The idea spread rapidly through the Colleges and residences in France, Belgium, Canada, England and throughout the Catholic world.

In 1870 Father Gautrelet's successor, Father Henri Ramière, asked Pius IX to grant this Papal Militia his blessing. In the letter which accompanied his petition he explained that it was a section of the AP, adapted for young Christians, to defend the cause of the Holy See with its own arms, especially frequent Communion and intense hours of study offered for this intention. He added that this Militia already had 100.000 members throughout the world and that, where it was present, participation in the life of the sacraments was increasing, not only among the students but also among the teachers and parents. In 1881, during the first International Congress of Lille, this resulted in it being said that: "the AP is a permanent eucharistic crusade".

In 1883 Father Ramière started a campaign in favour of children taking monthly communion in the parishes, so that those who went to the public and free elementary schools should not remain on the fringe of this sacramental renewal. Pius X's decrees of 1905 and 1910, respectively on Frequent Communion and Early Communion, were published to strengthen the eucharistic life of the faithful.

This resulted in the foundation, between 1911 and 1914, of the Eucharistic Leagues for children, adolescents and young people, with the object of putting these decrees into practice. In 1915 "the Children's Eucharistic Crusade" officially appeared within one of these groups - the Bordeaux group.

In 1932 the Father General of the Jesuits, Father Ledochowski, obtained Pius XI's recognition of the Eucharistic Crusade of the Apostleship of Prayer as a Primary Association.

In 1958 Pius XII approved the New rules of the Eucharistic Crusade with an autographed letter. Later the Father General John Baptist Janssens asked all the Jesuit Provincial Superiors to appoint competent Jesuits to this ministry: "three or four Fathers who devote themselves entirely to the Eucharistic Crusade, organize it solidly, train its promoters, direct the periodical publications and morally and religiously train hundreds of thousands of children and adolescents".

During the pilgrimage of 3.522 delegates of the Eucharistic Crusade of France to Rome in 1960, for the 50th anniversary of Pius X's Decree on early communion, John XXIII avoided using the word "crusade" in his allocution. Having been Nuncio in Turkey, he knew that the memory of the crusades must be avoided. The Eucharistic Crusade of France changed its name in 1962 to that of "Eucharistic Youth Movement". But it was not only a change of denomination: it involved a new impulse which imposed specific characteristics on the Movement; of these, one of the most important is that the Movement offers specific names, objectives and training methods for each stage of the child's life. Other countries like Italy, Spain, Chile, Argentina, Madagascar, etc., did the same, with a program adapted to the children and adolescents of each country.