The feast of the founder of the Solitaries of Monte Vergine was inserted into the Calendar of the Universal Church by Leo XIII. This monastic Congregation was widely diffused at one time in the South of Italy, but having greatly decreased in numbers it was amalgamated in the second half of the Nineteenth Century, with the Benedictines of Subiaco.
St. William, who died in 1142, was noted for austerity of his life and for his great gentleness toward others. He body rests now on the summit of the Parthenius, in the Basilica of Our Lady which he built, and where every year many thousands of pilgrims assemble to do honor to the Blessed Virgin. (Source: The New Roman Missal by Father Lasance)