“The Book of Armagh”, a manuscript written in the 9th century and containing the earliest copy of Saint Patrick's Confessio, states that in the year 441 AD Saint Patrick fasted and prayed on the summit of Croagh Patrick for forty days and forty nights following the example of Christ and Moses as part of his effort to convert Ireland to Christianity. He also built a church there.

On the summit the remains of an ancient stone fort and a trig point at 764m (2,510ft) can be seen. They are called St. Patrick's Chair.

Here, St Patrick is credited with driving snakes, demons and magicians out of Ireland, hurling them into the Demon’s Hollow or Log na nDeamhan, a lake at the north base of Croagh Patrick. It is said it burst up because of St Patrick’s powerful gesture.

For many years on the Holy Mountain the Black Bell of St Patrick or the “Clog Dubh” was a highly venerated relic. The bell, now in the National Museum in Dublin, is made from iron and dates from 600 to 900 AD.

According tradition, it was white, but became black because it was used as a weapon against the demons who came to torment St Patrick. This traditional story linked the bell directly to St. Patrick.

The Geraghty family, from Ballinrobe, owned the bell as Sir William Wilde stated in one of his book (1867). Every year, on Reek Sunday, the family used to bring the bell on the top of the Holy Mountain, where pilgrims were allowed to kiss it for a penny or for two pennies if affected by rheumatism pains.

Nowadays Croagh Patrick draws thousands of pilgrims who make the trek to the top on the last Sunday in July. In the area around the Holy Mountain Glaspatrick church stands. It was one of the original churches founded by St Patrick along with Aughagower and Teampall Padraig on the summit of the Holy Mountain.

According to legend, there is another connection to St Patrick. Totmael, who was the saint’s charioteer, is said to have died in this area and to have buried in Glaspatrick.