ILARO (Hilarus), POPE, saint. — Born in Sardinia, he was archdeacon of the Roman clergy at the time of s. Leone I. In 449 he was sent by the Pontiff as legate of the Apostolic See to the so-called “robbery of Ephesus.” Having rightly taken the side of Patriarch Flaviano, he was forced to withdraw in order to escape the wrath of Dioscoro and his supporters. He brought to Rome the appeal that Flaviano addressed to s. Leone; its text was discovered 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.
Having become pope, he had two oratories built beside the Lateran Baptistery, one of which, dedicated to s. Giovanni Evangelista, still exists; on the door’s architrave there is an inscription expressing gratitude to his liberator: «Liberatori suo b. Iohanni Evangelistae Hilarus episcopus, famulus Christi».
His seven-year pontificate (461–68) was not marked by major events. His extant letters concern almost exclusively southern Gaul. Immediately after his election, I. addressed a letter to Leonzio, bishop of Arles, to restore the primatial see to that city (MGH, Epistolae, III, p. 23, n. 16); it does not seem, however, that Leonzio showed much willingness to become the Pope’s apostolic vicar in France. In an encyclical letter of 3 December 462 to the bishops of southern Gaul, I. ordered the annual provincial synods and issued precepts concerning the duty of residence and the alienation of ecclesiastical property. For Spain, where Silvano of Calahorra had performed irregular ordinations, he summoned a Synod in Rome, held on 19 November 465 in the basilica of S. Maria Maggiore, dealing with disciplinary questions and the election of bishops. The period of peace that Rome enjoyed under I.’s pontificate made possible the enlargement of the Lateran and the restoration of churches damaged by the Vandals’ sack. Died on 29 February 468, the day on which his feast, previously celebrated on 10 September, was transferred.