It is related that owing to the hardships of the times the people could make very little, if any, offerings for Masses, with the result that the Archdeacon had mornings free to offer his Holy Mass for any intention he wished. He availed himself of the opportunity of which he was very pleased by offering one hundred Masses for the relief of the Souls in Purgatory. These hundred Masses for the relief of the Holy Souls in Purgatory were completed only about one week before the Apparition took place.
On the evening of August 21st , 1879 Mary McLoughlin, the housekeeper to Archdeacon Cavanagh was astonished to see the outside south wall of the church bathed in a mysterious light; there were three figures standing in front of the wall, which she mistook for replacements of the stone figures destroyed in a storm. She rushed through the rain to her friend Margaret Byrne’s house.
After a half hour Mary decided to leave and Margaret’s sister Mary agreed to walk home with her. As they passed the church they saw and amazing vision very clearly: Standing out from the gable and to the west of it appeared the Blessed Virgin, St. Joseph and St. John. The figure of the Blessed Virgin was life-size, while the others seemed to be neither as large nor as tall. They stood a little away from the gable wall about two feet from the ground. The Virgin was erect with her eyes toward Heaven, and she was wearing a large white cloak hanging in full folds; on her head was a large crown. Also present was a lamb on an Altar surrounded by Angels worshipping the lamb. The lamb clearly representing Jesus.
Mary Byrne ran to tell her family while Mary McLoughlin gazed at the apparition. Soon a crowd gathered and all saw the apparition. The parish priest, Archdeacon Cavanaugh, did not come out, however, and his absence was a disappointment to the devout villagers. Among the witnesses were Patrick Hill and John Curry. As Patrick later described the scene: ‘The figures were fully rounded, as if they had a body and life. They did not speak but, as we drew near, they retreated a little towards the wall.’ Patrick reported that he got close enough to make out the words in the book held by the figure of St. John.
An old woman named Bridget Trench drew closer to embrace the feet of the Virgin, but the figure seemed always beyond reach. Others out in the fields and some distance away saw a strange light around the church. The vision lasted for about three hours and then faded. For more on the apparition see www.knockshrine.ie
The Archdeacon did not see the apparition himself but he fully believed the credible nature of the visionaries’ accounts. He later served as a member of the Commission of Enquiry established in 1879 to investigate the authenticity of the Apparition. After the apparition, Archdeacon Cavanagh became known not only throughout the length and breadth of Ireland, but also all over the world. He received correspondence from every quarter and many of the letters were published in the Irish, British and Foreign Press in 1880 and the following years.