Pope Hilarius

His opposition to the condemnation of Flavian of Constantinople incurred the enmity of Dioscurus of Alexandria, who attempted to prevent him from leaving the city.

Much of his pontificate was spent in maintaining ecclesiastical discipline in conformity with canon law, and in settling jurisdictional disputes among the bishops of both Gaul and Spain.

Hilarius vigorously opposed the condemnation of Flavian of Constantinople,[4] pronouncing the single word in Latin, "Contradicitur", annulling the sentence in Leo's name.

[5] As pope, he continued the policy of his predecessor, Leo I, who, in his contest with Hilary of Arles, had obtained from Emperor Valentinian III a famous rescript of 444 (called Novel 17) confirming the supremacy of the bishop of Rome.

In 463, Mamertus of Vienne had consecrated a bishop of Die, although this Church, by a decree of Leo I, belonged to the metropolitan Diocese of Arles.

When Hilarius heard of it, he deputed Leontius of Arles to summon a great synod of the bishops of several provinces to investigate the matter.

The metropolitan rights of the See of Embrun over the dioceses of the Maritime Alps were protected against the encroachments of a certain Bishop Auxanius, particularly in connection with the two Churches of Nice and Cimiez.

Bishop Silvanus of Calahorra had violated the church laws by his episcopal ordinations, and the pope was asked for his decision.

The request was granted and the Synod of Tarragona confirmed the nomination of Irenaeus, after which the bishops sought the pope's approval.

He also erected a chapel of the Holy Cross in the baptistery, convents, two public baths, and libraries near the Basilica of St. Lawrence outside the Walls.