Father Diego is a member of the Society of Missionaries of Africa (White Fathers). He has worked in Sudan, Algeria, Egypt, Tunisia where he directed the Library of Religious Sciences in Tunis, and was a member of the Groupe de Recherches Islamo-Chrétien (GRIC). He holds a BA in Arabic Studies and Islamology from PISAI and a PhD in Theological and Religious Studies from Georgetown University.

His research and publications focus on the intellectual history of Islamic-Christian relations and the reciprocal theological insights that this history has bequeathed to Christians and Muslims today. In January 2014, Father Diego returned to the PISAI to teach Islamic theology, the Koran and Arabic grammar. He was also Director of Studies at the PISAI until his appointment as President of the Institute in September 2018. He is also a Consultor of the Pontifical Council for Interreligious Dialogue and a collaborator of the National Office for Ecumenism and Interreligious Dialogue (UNEDI) of the Italian Bishops’ Conference.