Saint Mary's College C.S.Sp. (Congregatio Sancti Spiritus) is an all-boys' primary & secondary school run by the Congregation of the Holy Spirit and located in Rathmines, County Dublin, Ireland. The school was founded in 1890 and was closed between 1916 and 1926. Rugby is the major sport and the school colours are blue and white. The Senior School Principal is Mr. Denis Murphy and the Senior School Deputy Principal is Mr. Brian Moore. The Junior School Principal is Mrs. Mary O'Donnell and the Junior School Deputy Principal is Mr. Brian Barron The College Motto is 'Fidelitas in Arduis' - Latin for 'faithfull in difficulty '. St. Mary's opened in 1890 with only 34 students but this number increased to 115 by the end of that first school year. The College closed in July 1916 for a variety of reasons including mounting debts, lack of staff and the necessity to relocate Holy Ghost seminarians from war-torn Europe. Due to popular demand led by the then Archbishop of Dublin, St. Mary's reopened in 1926. The College sports ground in Kenilworth Square was purchased in 1947. It was immediately levelled and seeded and was ready to be used in 1950.