And in the cause of Perigenes, in the title of his Epistle, he thus enumerates the Provinces under this Bishop: Rufo & coeteris Episcopis per Macedoniam, Achaiam, Thessaliam, Epirum veterem, Epirum novam, Praevalin, & Daciam constitutis. And Pope Xistus (Sixtus?) in a decretal Epistle to the same Bishops: Illyricanae omnes Ecclesiae, ut a decessoribus nostris recepimus, & nos quoque fecimus, ad curam nunc pertinent Thessalonicensis Antistis, ut sua sollicitudine, siquae inter fratres nascantur, ut assolent, actiones distinguat atque definiat; & ad eum, quicquid a singulis sacerdotibus agitur, referatur. Sit Concilium, quotiens causae fuerint, quotiens ille pro necessitatum emergentium ratione decreverit. And Pope Leo I. in his decreatal Epistle to Anastasius Bishop of Thessalonica: Singulis autem Metropolitanis sicut potestas ista committitur, ut in suis Provinciis jus habeant ordinandi; ita eos Metropolitanos a te volumus ordinari; maturo tamen & decocto judicio.
Occidental Illyricum comprehended Pannonia prima and secunda, Savia, Salmatia, Noricum mediterraneum, and Noricum ripense; and its Metropolis was Sirmium, till Attila destroyed this city. Afterwards Laureacum became the Metropolis of Noricum and both Pannonias, and Salona the Metropolis of Dalmatia. Now the Bishops of Laureacum and Salona received the pallium from the Pope: and Zosimus, in his decretal Epistle to Hesychius Bishop of Salona, directed him to denounce the Apostolic decrees as well to the Bishops of his own, as to those of neighboring Provinces. The subjection of these Provinces to the See of Rome seems to have begun in Anemius, who was ordained Bishop of Sirmium by Ambrose Bishop of Millain, and who in the Council of Aquileia under Pope Damasus, A.C. 381, declared his sentence in these words: Capus Illirici non nisi civitas Sirmiensis: Ego igitur illius civitatis Episcopus sum. Eum qui non confitetur filium Dei aeternum, & coeternum patri, qui est sempiternus, anathema dico. The next year Anemius and Abrose, with Valerian Bishop of Aquileia, Acholius Bishop of Thessalonica, and many others, went to the Council of Rome, which met for over-ruling the Greek Church by majority of votes, and exalting the authority of the Apostolic See, as was attempted before in the Council of Sardica.