The Albanoi (, Albanoi; ) were an Illyrian tribe. They were possibly first mentioned by Hecataeus of Miletus (550-476 BCE) under the name Abroi. Ptolemy (200-118 BCE) is the first author who mentions them under the name Albanoi. Their central settlement was called Albanopolis () and was located roughly between the Mat and Shkumbin rivers, in central Albania. Zgërdhesh has been identified as the likely location of Albanopolis. Stephanus of Byzantium who reproduced Hecataeus added an entry for another settlement named Arbon in Illyria whose inhabitants were called Arbonioi or Arbonites. Another Arbon was recorded by Polybius. John of Nikiû wrote in the 7th century CE about a people known as Arbanitai in the Greek translation of the manuscript.
In the Middle Ages, the names Albanoi and Arbanitai/Albanitai referred to medieval Albanians as an ethnic group. The equivalent terms in Latin are Albanenses/Arbanenses, in Slavic Arbanasi and later in Turkish Arnaut. These names reflect the Albanian ethnic endonym Arbëreshë/Arbëneshë, which itself derives from Albanoi. In the archaeological record, the Albanoi are mentioned on a funeral inscription in Stobi and Albanopolis is mentioned on another funeral inscription near Scupi. Another ethnonym, Arbaios found in Phoenice is likely linked to them.
Ancient and medieval literature
The Albanoi may have likely first appeared under the name Abroi in ancient literature. The Abroi may have been a constituent tribe of the larger group of the Taulantii. They are first mentioned by Hecataeus of Miletus (550-476 BCE) in fragment 69 of Periodos Ges. Hecataeus places them near the Taulanti who lived along the Adriatic and the Enchelei. In 19th century and 20th century cartographies, they are variously placed in the upper Devoll or the coastal area between Mat and Shkumbin rivers. Their name may have actually been Arboi as Abroi may have been produced via a metathesis, another linguistic process or a common misassociation by Hecataeus of their name with the ancient Greek term abros to better adapt it to Greek. The name Arboi directly connects them to the later Albanoi who lived in the same region. Stephanus of Byzantium who copied much of the work of Hecataeus in the 6th century CE added another entry about a city named Arbon in Illyria per Polybius and identified its demonyms as Arbonios and Arbonitis.
Polybius (200-118 BCE) mentions a location named "Arbon" in his description of the Illyrian Wars. "Arbon" in a series of mistranslations has been named an "island" or a "city" even though Polybius never mentions it as such. The place has not been identified, and it is unlikely that it refers to the northern Adriatic island of Rab (attested for the first time as Arba by Pliny). An interdisciplinary reading of the passage indicates that "Arbon" might actually have been in central Albania, roughly in the same location as the later Albanopolis (Ptolemy) and Arbanon (Anna Komnene). Wilhelm Tomaschek (1841-1901) considered Arbon to be the "first attestation of the modern name of Albania".
Ptolemy (100-170 CE) is the first author who mentions the ethnonym of the Albanoi in Geographia. The Albanoi are mentioned in the third book of Geographia. They were a people who lived in the region between Mat and Shkumbin and held the settlement Albanopolis. Johann Georg von Hahn first noted that the suffix -polis ("city") was probably added at a later date by other authors as in other editions it is mentioned as "Albanos polis" or "Albanos". Zgërdhesh has been identified as the likely location of Albanopolis. It is not certain if its location corresponds to the region mentioned as Arbanon mentioned by Anna Komnene in the Alexiad about events related to the First Norman invasion of the Balkans(1081). An indication of movement from higher altitudes in a much earlier period has been detected in the distribution of Albanian place names ending in -esh, derives from the Latin -ensis (Vulgar Latin -ēsis), between the Shkumbin and the Mat rivers, with a concentration between Elbasan and Krujë.