 Little information is available regarding his early years.It is presumed that he joined the Order of St. Augustine around the year 1272, and he is first mentioned in the surviving historical records in the year 1283 in the capitular acts of the Augustinians’ Roman province as a recently appointed lecturer in the Convent of Viterbo, meaning that he must have spent the previous five years from 1278 to 83 in the University of Paris, because the Augustinian Order required its lecturers to be trained in Theology in that city for a duration of five years.Giacomo returned to Paris soon after his appointment in Viterbo because his name is again mentioned in the capitular acts in 1288, where he is mentioned as holding a Bachelor of Theology degree from the University of Paris.