The Jesuits bought Tullabeg in 1818 (dedicated it to St Stanislaus) and opened a preparatory school for boys destined to go to Clongowes Wood College, Kildare. St Stanislaus College gradually developed as an educational rival to its sister school. It merged with Clongowes Wood College in 1886. Tullabeg then became a house of Jesuit formation: novitiate (1888-1930), juniorate (1895-1911), tertianship (1911-1927) and philosophate (1930-1962). In 1962, it was decided that the students of philosophy should be sent abroad for study. Tullabeg subsequently became a retreat house and was closed in May 1991.

The papers of St Stanislaus College include information on a history of the area around Tullabeg, building and property (1912-2004), correspondence with Superiors (1881-1971), finance (1912-1990), documents on Jesuit training (1818-1962), retreat house (1949-1960) and artworks (1940-1991).

Material is in the form of letters, reports, architectural plans, notes, maps and photographs (1902-1990). Programmes for plays include Shrovetide at St. Stanislaus College, Tullamore; ‘The Man with the Iron Mask’, ‘All at Coventry’ and ‘The Smoked Miser’ (1885) and for ‘Caitlín Ní Uallacáin’ and ‘Cox and Box’ and details Jesuits who performed (1925).

Copy of the book, "Some Notes on the History of The Fox Family of Kilcoursey in the King's County, Ireland" written by M E Stone first published in Chicago in 1890. The front page is a copy of a letter dated 8 August 1936 from Arthur Fox in Madison, Wisconsin, United States of America, to his grandson, Ripley Fox. He notes that the book was originally given by the author, M E Stone, to Arthur Fox's nephew, William Adamson.

Some Bibliographical Help in Preparing Retreats . Reprinted 1936 with “One Hundred Jesuit Ascetical Writers; & “A Hundred Books for Ascetical Students”. Selected by Archbishop Goodier. With signature of Fr Michael Pelly SJ on the cover.

Bound volume recording Sodality Attendances.

Three fragmentary draft or sketch maps on tracing paper of south and west Offaly dating to c.1808, and a fourth of the King's Channel area , County Waterford, dating possibly to Larkin's survey of County Waterford in 1818.

Large sketch map of portion of bogland in dispute between Lord Digby and Peter Quinlan versus Michael Healion. Bog in dispute is highlighted in green.
Scale of sixty six feet to one inch.