Historical Archives of the Pontifical Gregorian University (APUG) own a complex and heterogeneous documental material: manuscripts, printed texts noted by author or teacher, sometimes considered hybrids printed-manuscript. The use of archival or library standards are not sufficient to express this complexity. In addition to represent the physical structure, state of conservation and restoration, it was necessary to bring out context and network of relationships among documents, agents, activities, places, events and periods to reconstruct the history of education, models, subjects taught and their evolution within the Roman College (Jesuits school) and influence in Europe and in the world. We present the problem, how it was solved and the methodology used to create an OWL ontology developed in a bottom-up approach: starting from the analysis of real data, using an iterative process, we have reached interoperability and alignment with international standards (CIDOC-CRM, EAC, EAD, EDM, FRBR-oo, etc.). Each class, property and instance is identified by URI to use as Linked Data.