My studies are raising the question about the geographical, linguistic, religious, cultural and mental borders of the multi-layered legacy in the centres and peripheries of the Medieval Worlds. I have analyzed the Europe-wide intellectual attraction and radiance of the Parisian abbey of Saint-Victor in the mirror of its exegetical and theological production, focusing on the various European areas. Then, I have broadened my panorama to reconstruct European religious and intellectual identities by conducting extensive research on texts of Christian-Muslim encounters and perceptions in Europe, specializing on early Christian polemics against Islam, the linguistic and religious borders between Christians, Jews and Muslims, processes of religious and cultural passages, entanglement and dis/integration among the members of the three monotheisms in the Carolingian and Iberian Worlds. A new research field I try to establish is methodologically sound Transcultural Studies and Palaeography.