HILARUS, Pope, Saint. - Born in Sardinia, he was archdeacon of the Roman clergy at the time of St. Leo I. In 449 he was sent by the Pontiff as legate of the Apostolic See to the so-called "robber council of Ephesus." Having rightly taken his stand on the side of the patriarch Flavian, he was forced to withdraw in order to escape the wrath of Dioscorus and his partisans. He brought to Rome the appeal that Flavian addressed to St. Leo, the text of which was rediscovered in 1882 by A. Amelli in a manuscript of the Capitular Library of Novara and published by him in S. Leone Magno e l'Oriente (1882); in turn Th. Mommsen reproduced the manuscript, in Neues Archiv, 11 (1886), pp. 362-64.
After becoming pope, he had two oratories built alongside the Lateran Baptistery, one of which, dedicated to St. John the Evangelist, still exists; on the architrave of the door one reads the inscription full of gratitude for his liberator: «Liberatori suo b. Iohanni Evangelistae Hilarus episcopus, famulus Christi».
His pontificate of seven years (461-68) was not marked by great events. His surviving letters refer almost exclusively to southern Gaul. Immediately after his election, H. addressed a letter to Leontius, bishop of Arles, to restore the primatial see to that city (MGH, Epistolae, III, p. 23, n. 16); it does not appear, however, that Leontius showed himself too willing to become the Pope's apostolic vicar in France. With an encyclical letter of 3 Dec. 462 to the bishops of southern Gaul, H. ordered annual provincial synods and gave precepts on the duty of residence and on the alienation of ecclesiastical property. For Spain, where Silvanus of Calahorra had performed irregular ordinations, he convoked a Synod at Rome, held on 19 Nov. 465 in the basilica of St. Mary Major, dealing with disciplinary questions and the selection of bishops. The period of peace that Rome enjoyed under the pontificate of H. made possible the enlargement of the Lateran and the restoration of the churches damaged by the sack of the Vandals. He died on 29 Feb. 468, the day on which his feast has been reported, which was previously celebrated on 10 September.