In July 1837 Catherine McAuley accompanied four Sisters of Mercy in the ship the Hercules to Cork City. Bishop John Murphy and Miss Barbara Gould invited the Sisters and sponsored the new community in No 4 Rutland Street. They lived there until 1852, when a new Convent was built on the site of the old Dominican Priory at St. Maries of the Isle.

They visited the sick and poor in their home and opened a House of Mercy for homeless women and orphans. This resulted in their being called the ‘Sick Poor Order’.  The first Mercy Hospital in Ireland was opened in 1857. This expanded the ministry of the Sisters to include nursing, teaching, and social services.

Foundations were made from St. Maries of the Isle in Cobh, Bantry, Templemore, Co Tipperary, Ballindeasig, Passage West, Mayfield, Bishopstown, in Cork and to Kenya, Peru and the Phillipines.

Foundations were also made in Bermondsey and Sunderland, England.