In 1943, the Marianists of the University of Dayton founded The Marian Library to commemorate the triple centennial to be celebrated in 1949-1950: the arrival of the Marianists in the United States (1849); the death of Father William Joseph Chaminade, founder of the Society of Mary (1850); and the founding of the University of Dayton (1850).
        The Marian Library offers its resources to all qualified students and scholars who need an extensive collection of books, periodicals, and other materials centered on studies related to Mary, the Mother of Jesus. This collection of more than 150,000 items,  dating from the beginning of printing up to the present day, comprises works in more than fifty languages. It includes a general reference collection with resources in patristics, biblical studies, christology, ecclesiology, spirituality, church history, hymnography, iconography, general and specialized bibliography.
        The Marian Library is located with the Roesch Library, the main library of the University of Dayton. Roesch Library offers scholars a collection of more than 1,250,000 volumes, more than 3,000 periodical titles, the facilities of a nationwide interlibrary loan service, and the possibility of extensive online database searches.
        The Marian Library issues a multilingual journal, Marian Library Studies (New Series), devoted to the publication of original and scholarly research in all aspects of the field of Marian Studies:  editions of early texts, historical research and its documentation, historical bibliography, as well as comparative studies in such areas as religion, archaeology, iconography, symbolism, theological anthropology, and psychology.
        Because The Marian Library is the largest and most comprehensive collection in the world devoted to its specialty, it was fitting that an institute be organized to allow scholars and students to exploit its riches through research of all kinds, especially the preparation of theses leading to advanced degrees in theology with specialization in Marian studies.
        In 1975, an institute of graduate studies in theology was founded in affiliation with the Pontifical University Marianum, directed by the Servants of Mary (Servites) in Rome. The Sacred Congregation for Catholic Education approved the International Marian Research Institute (IMRI) on November 5, 1975. Since 1975, IMRI has organized annual summer schools at the graduate level to promote the programs of Marian Studies established by the Marianum and adapted to the needs of students in the United States and abroad. Students can prepare for a licentiate and doctorate in theology, with a concentration in Marian studies, earn a certificate in Marian studies, or gain credit hours toward a master's degree granted in conjunction with the Department of Religious Studies at the University of Dayton.
        After the Apostolic Constitution Sapientia Christiana established new  rules to be observed in the preparation for and granting of pontifical degrees, new IMRI statutes were developed and approved in 1983. IMRI is incorporated into the Faculty of Theology Marianum and is empowered to grant the Licentiate of Sacred Theology (S.T.L.) and Doctorate of Sacred Theology (S.T.D.) degrees, following the prescribed courses of study.
        To understand IMRI, acquaint yourself with its "foundation" documents: the program of pontifical degrees as outlined in Sapientia Christiana; the Statuti of the Pontifical Faculty Marianum (Rome); the "Student Guide to Pontifical Degree Programs" at the International Marian Research Institute (University of Dayton); and, lastly, the Letter of the Congregation for Catholic Education, "The Virgin Mary in Intellectual and Spiritual Formation."