Just days before the historic 2018 Papal visit to Ireland we take a look at the 1879 apparition of the Virgin Mary in Knock, County Mayo, which an Irish journalist in 2009 suggested wasn't real.

Thousands of people from all over Ireland make a pilgrimage to Knock, County Mayo, every year for the August 21 anniversary of the famed 1879 apparition of the Virgin Mary there. This year the anniversary came as Ireland prepared for the arrival of Pope Francis to Ireland for the World Meeting of Families 2018.

During the Pope's visit, he will attend events at Croke Park in Dublin, Phoenix Park and also the Knock Shrine in County Mayo where thousands of pilgrims flock annually for the anniversary and throughout the year.

In 2009 the anniversary novena's theme was 'witness to hope,' and it focused on honoring the 15 local witnesses of the 1879 apparition, as well as highlighting the hope and prayers for the renewal of the church in Ireland. At that time of that anniversary, when 10,000 thronged the County Mayo basilica in search of another vision, Irish journalist Eoghan Harris suggested that the 1879 apparition of the Virgin Mary was a fake.

Read more: Do we owe Sinéad O’Connor an apology for speaking the truth about church child abuse?

He wrote in the Sunday Independent that his grandfather, a farmer from near the area, believed (like many at the time) that the apparition was created by two local policemen with a magic lantern – a device that was widespread in the 19th century, which allowed a small lightbox to project an image on a wall.

The reported apparition began on the evening of August 21, 1879. Mary McLoughlin, the housekeeper to the parish priest of Knock, County Mayo, 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 agreed to walk home with her.

As they passed the church they saw an amazing vision very clearly: standing out from the gable and to the west of it appeared the Virgin Mary, St. Joseph and St. John. The figure of Mary was life-sized, while the others seemed to be neither as large nor as tall.

The Knock Shrine Basilica.

The Knock Shrine Basilica.

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.

Read more: A brief history of Irish apparitions

Mary Byrne ran to tell her family while Mary McLoughlin gazed at the apparition. Soon a crowd of fifteen gathered, young and old, 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.

The next day, a group of villagers went to see the priest, who accepted the report as genuine. He wrote to the diocesan Bishop of Tuam, then the Church set up a commission to interview a number of the people claiming to witness the apparition.

The diocesan hierarchy was not convinced, and some members of the commission ridiculed the visionaries, alleging they were victims of a hoax perpetrated by the local Protestant constable.

But the ordinary people were not so skeptical, and the first pilgrimages to Knock began in 1880.

Two years later Archbishop John Joseph Lynch of Toronto made a visit to the parish and claimed he had been healed by the Virgin of Knock.

Read more: No to Pope Francis - I am a devout Irish Catholic but refuse to see him in Ireland

* A version of this article was originally published in November 2009.