In the last two hundred years, Saint Louis Marie Grignion de Montfort’s teachings through the “Treatise on True Devotion to the Blessed Virgin” have been converted into a common reference and eloquent testimony of the Supreme Pontiffs. This small and simple work, which is rich in doctrine, has implicitly influenced the writings and documents of the Holy Fathers, who have expressed their gratitude to the saint by encouraging the Church to deepen Her Marian spirituality.