 After the completion of his studies, Giacomo was appointed Master of Theology in either 1292 or 1293, and taught in Paris for the next seven years, during which time his output was extensive as all of his works in the fields of speculative theology and metaphysics date from this time.Around the year 1300, he was named as a member of the governing council of the Augustinian Roman Province by the Augustinians’ General Chapter, and in May 1300, he became regent master of the order's "studium generale" in Naples.These two years proved to be the last of his academic career, because Pope Boniface VIII appointed him as Archbishop of Benevento in September 1302, possibly as a sign of gratitude for Giacomo's support for the Pope against the King Philip IV in his treatise, "De regimine christiano" ("On Christian Rulership").