Urban IV. having brought Thomas to Italy, Clemens IV. kept him there as long as he lived, making him a professor in the university established by Innocent IV. within the Roman Curia, and as such carried him about from city to city as the Papal Court removed, and had him lecture on theology wherever the Court was staying. He also set him to the work of writing commentaries on part of the Scripture: Job, the Psalms, Canticles, Isaiah, Jeremiah, and Paul’s Epistles, besides his _catena_ of comments on the Gospels gathered from the Latin fathers. Most important of all for our purposes, he asked him to prepare the service for Corpus Christi Day—a festival established in 1264. It was for this that Thomas wrote four of the hymns which have given him his place in the annals of hymnology, and those are his finest. And it is said that he also began his _Summa_ in these years, but that I doubt. But in 1269 Clemens died, and it was two years before another Pope was elected. Thomas took the opportunity to escape out of the throng and noise of the Curia, and made his way back to France and to his old manner of life. He came back to Paris and lectured in St. Jacques Street, but not as the head of the school. At Paris he now found critics as well as admirers. His doctrine that individuality is dependent upon matter was censured as involving a denial of immortality, and in 1269 he wrote a treatise, _Contra Averroistas_, to show that this was not a necessary or even a fair inference. In the same year we find him in London attending a Chapter General of his order. In 1271 the vacancy in the papacy ended with the selection of Gregory X., one of the best of the popes. Thomas was recalled to Italy and offered the Archbishopric of Naples, doubtless at the suggestion of Charles of Anjou, whose hands were red with the blood of the young Conradin. Thomas wisely declined it, and when, in 1272, he agreed to go to Naples as a teacher of theology, it was with the reservation that this should not bring him into close relations with the Court. Enough of his Ghibelline traditions clung to him to make him abhor the murderer of his kinsman. So in Naples he taught, and wrote at his _Summa_, and prayed and saw visions—his biographers say—until one day the Pope summoned him to a General Council at Lyons, with the view of proclaiming a new crusade. He obeyed the summons, but when he reached the Cistercian monastery of Fossa Nuova, on the hills above the Pontine Marshes, below Rome, he fell ill and died, March 7th, 1274. Of course the Italians knew he was poisoned, and even Dante countenances the report. The Pontine Marshes in spring are so wholesome that no other hypothesis could account for his death! His friend Bonaventura reached Lyons, but died during the sessions of the council. His earlier friend and master, Albert the Great, although his senior by thirty years, outlived him by six, dying in 1280.