Fr. Prospero was born at Birgu, Malta on 24 December 1925, son of Vincent and Amelia nee’ Gatt and was named Stanley. His primary education was at the Mater Boni Consili school, Rahal il-Gdid and St. Catherine’s, Sliema. He continued his secondary education at the Lyceum.

In 1943 he joined the Augustinian Order where he was given the name Prospero and his first two years of study in Philosophy were at the Augustinian Theological College at the convent in Rabat, Malta. In 1946 he was sent to Rome to continue his studies in Theology at the St. Monica International College and on 25 March 1950 he was ordained a priest at the Lateran Basilica.

After his ordination he continued his theological studies at the Pontifical Gregorian University where in 1953 he obtained a doctorate, his thesis being ‘The Atonement and God in Modern English Theology.’ Thereafter he studied Scripture at the Pontifical Biblical Institute, Rome until 1952 when he returned to Malta where he taught at the Augustinian Theological College and at the Mater Admirabilis Training College, Rabat. At the same time, he was responsible for the formation of Augustinian students. In 1957 he obtained a scholarship at Oxford University to study the Hebrew language and educational system. Later he was invited to collaborate with Professor A. J. Arberry in his studies at Cambridge University regarding Maltese Literature and the national Poet Fr. Karm Psaila. In 1959 he returned to the Augustinian Community at Rabat where, for another two years, he assumed teaching duties.

Back to Rome in 1961 he continued his biblical studies and distinguished himself not only in academic circles but also in other activities in the Vatican. On his arrival in Rome, amongst other duties, he was nominated secretary to the Pope’s Vicarate at the Vatican City.

At the start of the seventies he was co-founder of the Agostinianum Patristic Institute and was appointed its first president. Apart from his work at the Agostinianum , over the years he continued his involvement in the academic field at various other universities including the Pontifical Biblical Institute; the Pontifical Lateran University and LUMSA. He also authored a long list of articles and books.

In 1984 he was nominated Consultant to the Congregation of the Doctrine of Faith; in 1998 as Apostolic visiting lecturer at seminaries in India; between 2002 and 2003 as a member of the Ecumenical Commission for discussions with the Orthodox Church in Sofia; in 2003 as a member of the Pontifical Theological academy and in 2004 as a member of the Pontifical Biblical Commission.

Notwithstanding his wide involvement in the academic field, which doubtless took a lot of his time and energy, Fr. Prospero was always a glowing presence in the religious communities of which he formed part and as a priest he always carried out his pastoral duties amongst which as an assistant of the Rinascita Christiana.

On 6 January 2012 Pope Benedict XVI recognised Fr. Prospero’s distinguished service to the church and announced that he was to be appointed a Cardinal at a public consistory. This was held at the Vatican on 18 February 2012. Simultaneously he was nominated as Titular Archbishop of St. Leone and he was consecrated bishop on 8 February 2012 at St. John’s Co-Cathedral, Malta.