The Albanian language is a distinct Indo-European language that does not belong to any other existing branch. Sharing lexical isoglosses with Greek, Balto-Slavic, and Germanic, the word stock of Albanian is quite distinct. Hastily tied to Germanic and Balto-Slavic by the shift of PIE * ā to * ō in a supposed "northern group", Albanian has proven to be distinct from the other two groups as this vowel shift is only part of a larger push chain that affected all long vowels. Admittedly, Albanian does share with Balto-Slavic two features: a lengthening of syllabic consonants before voiced obstruents and a distinct treatment of long syllables ending in a sonorant. However, Albanian is best known for its singular conservatism, having retained the distinction between active and middle voice, present and aorist, three series of tectal consonants before front vowels (e.g., palatals, velars, and labio-velars), and initial PIE * h4 as an h .
Albanian is considered to have its closest linguistic affinity to and to have evolved from an extinct Paleo-Balkan language, usually taken to be either Illyrian or Dacian or Thracian.
Even the name Albanian is of some dispute. It appears at the first time in the 2nd c. AD in Late Greek as Albanoí (later Byz Gk Arbanitai ) and thereafter in similar forms, including obsolete Albanian Arbër / Arbën ; however, these last two stem directly from Vulgar Latin * Albanus , most likely borrowed from Greek Albanoí ; the adjective too, arbëresh / arbënesh , are derived from Latin albanensis . This same name appears in Slavic and was used to name the town of Labëri "Laberia", from South Slavic labanĭja , from earlier * olbanĭja .
While it is considered established that the Albanians originated in the Balkans, the exact location from which they spread out is hard to pinpoint. Despite varied claims, it seems that the Albanians came from slightly farther north (Kosovo) and inland (Northwest Macedonia) than would suggest the present borders of Albania, with a homeland concentrated in the mountains. The purely linguistic reasons are listed below.
Instead, given the overwhelming amount of shepherding and mountaineering vocabulary as well as the extensive influence of Latin, it is more likely the Albanians come from north of the Jireček Line, on the Latin-speaking side, perhaps in part from the late Roman province of Dardania from the western Balkans. However, archaeology has more convincingly pointed to the early Byzantine province of Praevitana (modern northern Albania) which shows an area where a primarily shepherding, transhumance population of Illyrians retained their culture. This area was based in the Mat district and the region of high mountains in Northern Albania, as well as in Dukagjin, Mirditë, and the mountains of Drin, from where the population would descend in the summer to the lowlands of western Albania, the Black Drin ( Drin i zi ) river valley, and into parts of Old Serbia. Indeed, the region's complete lack of Latin place names seems to imply little latinization of any kind and a more likely spot for the early medieval heart of Albanian territory, following the collapse of the Illyrian province.
The period during which Proto-Albanian and Latin interacted was protracted and drawn out over six centuries, 1st c. AD to 6th or 7th c. AD. This is born out into roughly three layers of borrowings, the largest number belonging to the second layer. The first, with the fewest borrowings, was a time of less important interaction. The final period, probably preceding the Slavic or Germanic invasions, also has a notably smaller amount of borrowings. Each layer is characterized by a different treatment of most vowels, the first layer having several that follow the evolution of Early Proto-Albanian into Albanian; later layers reflect vowel changes endemic to Late Latin and presumably Proto-Romance. Other formative changes include the syncretism of several noun case endings, especially in the plural, as well as a large scale palatalization.
A brief period followed, between 7th c. AD and 9th c. AD, that was marked by heavy borrowings from Southern Slavic, some of which predate the "o-a" shift common to the modern forms of this language group. Starting in the latter 9th c. AD, a period followed characterized by protracted contact with the Proto-Romanians, or Vlachs, though lexical borrowing seems to have been mostly one sided - from Albanian into Romanian. Such borrowing indicates that the Romanians migrated from an area where the majority was Slavic (i.e. Middle Bulgarian) to an area with a majority of Albanian speakers, i.e. Dardania, where Vlachs are recorded in the 10th c. AD. Their movement is probably related to the expansion of the Bulgarian empire into Albania around that time. This fact places the Albanians at a rather early date in the western or central Balkans.
Indeed, the center of the Albanians remained the river Mat, and in 1079 AD they are recorded in the territory between Ohrid and Thessalonika as well as in Epirus.
Furthermore, the major Tosk-Gheg dialect division is based on the course of the Shkumbin River, a seasonal stream that lay near the old Via Egnatia. Since rhotacism postdates the dialect division, it is reasonable that the major dialect division occurred after the Christianization of the Roman Empire (4th c. AD) and before the eclipse of the East-West land-based trade route by Venetian seapower (10th c. AD).
References to the existence of Albanian as a distinct language survive from the 1300s, but without recording any specific words. The oldest surviving documents written in Albanian are the "Formula e Pagëzimit" (Baptismal formula), "Un'te paghesont' pr'emenit t'Atit e t'Birit e t'Spirit Senit." (I baptize thee in the name of the Father, and the Son, and the Holy Spirit) recorded by Pal Engjelli, Bishop of Durrës in 1462 in the Gheg dialect, and some New Testament verses from that period.
The oldest known Albanian printed book, Meshari or missal, was written by Gjon Buzuku, a Roman Catholic cleric, in 1555. The first Albanian school is believed to have been opened by Franciscans in 1638 in Pdhanë. In 1635, Frang Bardhi wrote the first Latin-Albanian dictionary.