On August 21, 1879, two local women, Mary McLoughlin and Mary Beirne, were returning home in the rain. On passing the rear of the Knock village church, they saw a miraculous sight. Our Lady, St Joseph and St John the Evangelist appeared at the south gable of the church.

Mary was dressed in a large white cloak, fastened at the neck, with her hands and eyes facing upwards in prayer towards Heaven. She wore a brilliant crown with a gold rose.
St Joseph stood on her right hand side with his head bowed and inclined towards Our Lady. He too wore white robes.
St John the Evangelist stood on her left hand side, wearing a bishop’s regalia. He carried a book in both hands, which he had raised up, as if in preaching mode.
To the right of the three figures there was a large plain altar, on which was standing a lamb.

Behind the lamb a large cross could be seen. Angels were seen hovering around the lamb.
It is said that over the course of the two hours the apparition lasted, the two women called other passers-by to them to witness the spectacle.

A total of 15 official witnesses were recorded and the group recited the Rosary.

The sick and weary began making pilgrimages to the shrine in their thousands and the tradition continues up to today. Reports are ongoing of sick and disabled pilgrims believing they have received cures at Knock.

Claims average 20 to 30 each year, but none has yet been investigated by Church authorities.

August was selected as the appropriate month to focus attention on the devotion of Mary, as the feast day of Our Lady of Knock is August 21 while the feast of the Assumption is August 15.

The pilgrimage season is not limited to just August 14 – 22, as planned visits by groups take place from May each year.