Alfredo Schuster was born in Rome on 18 January 1880 of Bavarian family.
Orphan of father, when he was eleven years old he applied as a student at the monastery of St.Paolo Fuori Le Mura, where he later wore the Benedictine habit and followed the monastic profession, assuming the name of Ildefonso.
During his novitiate years he was in close contact with the blessed Placido Riccardi, who molded him to a robust spirituality founded on the meaning of his own nothingness and the absolute abandonment to the will of God.
On 19 March 1904 he received the priestly ordination in the Basilica of San Giovanni in Laterano, and at the age of 38 he was elected Abbot.
On July 21, 1929, Pope Pius XI ordered the abbot Schuster bishop for the Church of Milan, after having elevated him to the dignity of cardinals. His constant inspiration was St. Carlo Borromeo whose charity towards the unhappy and firmness in defending the integrity of the faith and the freedom of the Church, whose concern for the increase of participation in the sacraments and the Christian doctrine and assiduous presence next to the people especially through pastoral visit he imitated, implemented almost five times throughout the Diocese.
During the Second World War he remained in his city, occupied by the German troops, he implored with his intervention the destruction of Milan and rescued, without distinction of parts, the innumerable sufferings and the miseries caused by the conflict.
His passionate zeal is witnessed by the convocation of five Diocesan Synods and a Provincial Council, the celebration of Eucharistic and Marian Congresses, the edification and dedication of places of worship, the numerous and precise letters to the clergy and to the people, the renewal of the liturgical life, the impulse given to parish speakers and cultural centers, the revival of the Catholic daily, the support offered to Christian social commitment.
In 1942 he established the Pia Association “Pro Seminario” and nominated Ezia Fiorentino as diocesan secretary.
The feast of Pentecost of 1945 with Ezia Fiorentino constituted the Secular Institute of the Missionaries of the Royal Priesthood and he laid out its first Statute. Ezia Fiorentino President. Diocesan spiritual assistant Father Raineri Boga.
On August 14, 1954, obliged by the doctors to finally give himself a few days of rest, he retired to the seminary of Venegono Inferiore where, at the dawn of August 30, 1954, his industrious earthly existence ceased.
The corpse was transported to Milan between two unbroken wings of the crowd that knelt down, cried, prayed moved at the passage of the hearse. The factories were closed and all the bells sounded mourning. An overwhelming crowd filled the Duomo day and night to greet the hailed corpse.
On the 30 August 1975, on the third anniversary of his death, his successor, Cardinal Giovanni Montini, initiated the information process for the beatification process of the holy Archbishop who was proclaimed blessed by Giovanni Paolo II on 12 May 1996 during a solemn celebration in Saint Peter.