On Thursday, August 21, 1879, at about 8 pm, at Knock in Co. Mayo, Ireland, Mary McLoughlin, 45, and Mary Byrne, 29, saw "luminous figures" on the gable wall of the parish church. Surprised, the two women took a closer look—it was an apparition of Our Lady.
There were fifteen official witnesses to the apparition, all of whom saw the Virgin for nearly two hours. The driving rain prevented some of them from staying until the end. Others left and then came back, witnessing the same scene: the Blessed Virgin appeared life-size in the attitude of prayer, with her eyes turned up towards heaven, a crown on her head and wearing a large white cloak fastened to the neck. Next to her were Saint Joseph and Saint John the Evangelist. The onlookers also saw the body of a lamb above and resting on an altar.
No vocal message was communicated during this silent apparition, but miraculous healings were reported. In 1879, the diocesan archbishop instituted a commission of inquiry, which issued a positive report the following year. In 1936, Bishop Gilmartin, Archbishop of Tuam, opened a Medical Findings Office to scientifically study the alleged cures, and he created a new commission of inquiry that reiterated the positive conclusions of 1880.
Knock, the "Irish Lourdes," has continued to attract crowds. In 1979, Saint John Paul II came to Knock on one of his first trips. (1)
___________________________
(1) More recently, Pope Francis will visit Knock on August 26, 2018, during his stay in Ireland for the World Meeting of Families in Dublin
Adapted from Le Dictionnaire des apparitions, Fayard 2007 by Father René Laurentin and Knock Shrine