Catherine McAuley was born in Dublin in 1778. In 1824 she used her inheritance from an Irish couple she had served for twenty years to build a large House of Mercy where she and other lay women would shelter homeless women, reach out to the sick and dying and educate poor girls. The House on Baggot Street opened in 1827.

To give these efforts greater stability, Catherine and her co-workers founded a new religious congregation.On 12 December 1831, she and two others professed their vows as the first Sisters of Mercy. Before her death on 11 November 1841, Catherine founded convents and works of mercy throughout Ireland and England. Her main focus was the education for poor Catholics at at time when education was mainly reserved for members of the established Church of Ireland.