Father Charles Joseph Eugène de Mazenod gathered round him a group of priests in Southern France to preach the Gospel to the poor workers of the region. They became known as ‘Missionaries of Provence’ and other priests, attracted by their work, joined the group. In 1826 they received the title of Missionary Oblates of Mary Immaculate (Oblates) and approbation as a Congregation under simple vows in a Brief of Leo XII dated 17th February 1826.
In 1854 the Founder was invited by several Irish Bishops to establish an Oblate Mission in Ireland. Archbishop Cullen met with Fr Robert Cooke, who was on a mission to Dublin. He was an Irishman who had studied theology in Marseilles, and had then been ordained by the now Bishop Mazenod. He agreed to set up a base to enable the Oblates to work with the poor people of Kilmainham and, in 1856, the Oblates bought a farm in Inchicore as their base. Just one year later, the Founder was saying Mass in a church built on the site. Two years later, in 1858, the Oblates were asked to set up a reformatory school in Glencree.