Zoé Labouré, in religion Sister Catherine, entered the Daughters of Charity in Paris in April 1830. On the night of 18–19 July 1830, and again on 27 November 1830, the Blessed Virgin appeared to her in the chapel of the Sisters at 140 rue du Bac and entrusted her with the design of what would become the Miraculous Medal — struck since 1832 and now the most widely distributed sacramental in the Catholic Church.
Sister Catherine kept the secret of her role in the apparitions for the rest of her life, living in obscurity at the Enghien hospice at Reuilly; only her confessor Fr. Aladel and, shortly before her death, her superior knew. She died on 31 December 1876 and was buried in a triple coffin in the crypt of the community chapel at Reuilly.
On 21 March 1933, in preparation for her beatification (Pius XI, 28 May 1933), the body was exhumed after fifty-seven years. Bishop Chaptal, auxiliary of Paris, who presided at the exhumation, found the body incorrupt: the flesh flexible, the arms and joints supple, the eyes still blue and open with the corneas transparent, the religious habit unworn. The body was transferred to the chapel of the Rue du Bac. Catherine was canonised by Pius XII on 27 July 1947, and her body lies in a glass reliquary above the side altar of the chapel — directly beneath the spot where the Virgin had once stood — the eyes, remarkably, still open.