The coastal area of Vlorë was one of those Illyrian sites that had experienced pre-urban activity beginning from the 11th–10th centuries BCE.^[18] During the period of Euboean colonization of the area (early 8th century BC) the bay of Vlorë was associated with several Heroic traditions and the foundation of several settlements there,^[19] as the toponym Aulon suggest which is also known in local Eubean toponimity.^[20]

Due to its strategic position on the Adriatic Sea, especially the Bay of Vlorë, which forms a natural harbor, Vlorë occupied a significant place in classical antiquity as a base for trade by many peoples. Vlorë is considered one of the oldest cities in Albania and the region.^[d] In the Archaic era, the area was colonized by Ancient Greeks, who are traditionally believed to have founded Orikos, Thronion and Aulon on these shores.^[21] A large fortified port-town that was inhabited from the 6th century BCE to the 2nd century AD is placed, now partially submerged, in Triport, northwest of present-day Vlorë. It was delimited by three walls, the first of which dating back to the late 6th century BCE.^[22] The port activity in this site lasted from at least the archaic period to the medieval period.^[23] It has been suggested that a transfer of the ancient city from the site of Triport to the site of modern Vlorë occurred. The center of the modern city features walls dating from the 4th to the 10th centuries CE, as well as a wall, a quadrangular tower and ruins of a huse with ceramics dating back to the 3rd–4th centuries and to the 6th-7th centuries CE.^[24]

The archaeological site of Triport has been identified with ancient Thronion or Aulon.^[25] Thronion was attested by Pausanias (2nd century CE) as a Locrian–Euboean colony, but also by a dedication on a monument erected in Olympia, both accounts reporting that Apollonia conquered the city around 450 BCE. Aulon, from which Vlorë took its name, was mentioned for the first time by Ptolemy (2nd century CE) among the towns of the Illyrian Taulantii.^[26] Carl Patsch proposed the first location of Aulon in Triport being then transferred to the current location of Vlora, and Pierre Cabanes proposed the location of Thronion in Triport; those identifications are not in contradiction with each other.^[27] Other geographical documents, such as the Tabula Peutingeriana and Hierocles‘ Synecdemus, also mention Aulon. The city served as an important port of the Roman Empire, when it was part of Epirus Nova.^[28][29]

Aulon (Avlona) became an episcopal see in the 5th century. Among the known bishops are Nazarius in 458 and Soter in 553 (Daniele Farlati, Illyricum sacrum, VII, 397–401). The diocese at that time belonged to the papal Pentarchy. In 733, it was annexed with the eastern Illyricum, to the Patriarchate of Constantinople, and yet it is not mentioned in any Notitiae Episcopatuum of that Church. The bishopric had probably been suppressed for though the Bulgarians had been in possession of this country for some time, Avlona is not mentioned in the “Notitiae episcopatuum” of the Bulgarian Archbishopric of Ohrid.

During the Roman period, a Latin see was established and Eubel (Hierarchia catholica medii aevi, I, 124) mentions several of its bishops.^[28]