In the first part of this paper, we will describe the essential lines of an ontology (implemented in OWL) for the three archives of the Bibliotheca Iuris Antiqui (BIA). Namely, we will briefly outline the classes and the relations of this ontology and will give a graphic representation of its conceptual structure. In the second part, we will discuss the perspectives of development that the ontological form of a knowledge basis opens up. It is pointed out that, on the one hand, the ontological form allows the development of radically new forms of information search and retrieval and, on the other one, it allows to link and integrate in a natural way different knowledge bases, each one characterised by specific criteria of internal organisation. In this regard, the essential steps that need to be taken to bring about such an integration, and the possible benefits that will ensue, will be analysed.