According to the book by Teresa Santander Reseña sobre la Biblioteca y Archivo Universitarios (Review of the University Library and Archive) (1986), 3,834 works were added to the Library coming from the College of Archbishop Fonseca "when its restoration began" (p. 79). Since 1821 this building had been the home of the Colegio de los Irlandeses (Irish College), dedicated to the formation of the Irish Catholic clergy and governed by the Jesuits. When the latter were expelled, the Irish College benefited from the allotment of the books from the library of the Royal College

All books from this source were assigned number currens ranging from 135,000 to 142,100.