The steady growth of Tallaght in the 1960s led to its separation from the parish of Rathfarnham to which it had belonged for centuries. In 1969 Tallaght was incorporated into the newly created parish of Bohernabreena-Firhouse. But in September 1972 archbishop Dr Dermot Ryan entrusted Dominicans with the care of the Parish of St. Mary’s Tallaght. Initially this included all of Central Tallaght and Kilnamanagh before the latter became a separate parish in 1974.
St. Mary’s comprised four administrative districts and so three new churches were built: St Dominic’s in Millbrook (1975), St. Aengus’ in Tymon North (1975) and St. Martin’s in Old Bawn (1976), each with a small residential unit for its own Dominican team. Finally, St. Mary’s and its three daughter churches were divided into four parishes in 1985. St. Martin’s parish was returned to the care of the diocesan clergy in 1999.