Editing Pope Leo I (section)

===Various regional matters===
On several occasions, Leo was asked to arbitrate disputes in Gaul. Patroclus of Arles (d. 426) had received from [[Pope Zosimus]] the recognition of a subordinate [[primate (bishop)|primacy]] over the Gallican Church,{{sfn|Randers-Pehrson|1983|p=123-124}} which was strongly asserted by his successor [[Hilary of Arles]]. An appeal from Chelidonius of Besançon gave Leo the opportunity to assert the pope's authority over Hilary, who defended himself stoutly at Rome, refusing to recognize Leo's judicial status. Feeling that the primatial rights of the bishop of Rome were threatened, Leo appealed to the civil power for support and obtained, from [[Valentinian III]], a decree of 6 June 445, which recognized the primacy of the bishop of Rome based on the merits of Peter, the dignity of the city, and the legislation of the [[First Council of Nicaea]]; and provided for the forcible extradition by provincial governors of any bishop who refused to answer a summons to Rome.<ref>Henry Bettenson, Chris Maunder, ''Documents of the Christian Church'' (Oxford University Press 2011 {{ISBN|9780199568987}}), p. 24</ref> Faced with this decree, Hilary submitted to the pope, although under his successor, Ravennius, Leo divided the metropolitan rights between Arles and Vienne (450).

[[File:Priest celebrating Mass at Altar of Leo I in St. Peter's Basilica.jpg|thumb|left|Priest celebrating Mass at the Altar of Leo the Great with the ''[[Alessandro Algardi#The Fuga d'Attila relief|Fuga d'Attila]]'' relief by [[Alessandro Algardi]] in [[St. Peter's Basilica]]]]

In 445, Leo disputed with [[Dioscorus of Alexandria|Patriarch Dioscorus]], [[Cyril of Alexandria]]'s successor as [[Patriarch of Alexandria]], insisting that the ecclesiastical practice of his see should follow that of Rome on the basis that [[Mark the Evangelist]], the disciple of [[Saint Peter|Peter the Apostle]] and the founder of the Alexandrian Church, could have had no other tradition than that of the prince of the apostles.<ref name="dcb1911">{{cite book |last1=Bright |first1=W |editor1-last=Wace |editor1-first=Henry |title=Dictionary of Christian Biography |date=1911 |publisher=John Murray |location=London |edition=Christian Classics Ethereal Library, online |chapter-url=https://www.ccel.org/ccel/wace/biodict.html?term=Dioscorus%20(1),%20patriarch%20of%20Alexandria |access-date=2 August 2021 |chapter=Dioscorus (1), patriarch of Alexandria |page=266 |quote= We find him, [Dioscorus] ... in correspondence with pope Leo the Great, who gave directions, as from the see of St. Peter, to the new successor of St. Mark; writing, on June 21, 445, that "it would be shocking (nefas) to believe that St. Mark formed his rules for Alexandria otherwise than on the Petrine model" (Ep. 11)}} {{PD-notice}}</ref>

The fact that the African province of [[Mauretania Caesariensis]] had been preserved to the empire and thus to the [[Nicene Creed|Nicene]] faith during the [[Vandal]] invasion and, in its isolation, was disposed to rest on outside support, gave Leo an opportunity to assert his authority there. In 446 he wrote to the Church in Mauretania in regard to a number of questions of discipline, stressing the point that laymen were not to be appointed to the episcopate.<ref name=Crawley/>

In a letter to the bishops of [[Campania]], [[Picenum]], and [[Tuscany]] (443) he required the observance of all his precepts and those of his predecessors; and he sharply rebuked the bishops of [[Sicily]] (447) for their deviation from the Roman custom as to the time of [[baptism]], requiring them to send delegates to the Roman synod to learn the proper practice.

Because of the earlier line of division between the western and eastern parts of the [[Roman Empire]], [[Illyria]] was ecclesiastically subject to Rome. [[Pope Innocent I]] had constituted the [[metropolitan bishop|metropolitan]] of [[Thessalonica]] his [[vicar]], in order to oppose the growing influence of the [[Ecumenical Patriarch of Constantinople|patriarch of Constantinople]] in the area. In a letter of about 446 to a successor bishop of Thessalonica, Anastasius, Leo reproached him for the way he had treated one of the metropolitan bishops subject to him; after giving various instructions about the functions entrusted to Anastasius and stressing that certain powers were reserved to the pope himself, Leo wrote: "The care of the universal Church should converge towards Peter's one seat, and nothing anywhere should be separated from its Head."<ref>{{Cite web|url=https://www.newadvent.org/fathers/3604014.htm|title=CHURCH FATHERS: Letter 14 (Leo the Great)|website=www.newadvent.org}}</ref>

He succeeded in having an imperial patriarch, [[Timothy Salophakiolos]], and not [[Pope Timothy II of Alexandria|Timotheus Aelurus]], chosen as [[Pope of the Coptic Orthodox Church of Alexandria|Coptic Orthodox Pope of Alexandria]] on the murder of [[Greek Orthodox Patriarch of Alexandria|Greek Patriarch]] [[Proterius of Alexandria]].<ref name=Kirsch1910 />