Slavic settlement of the Eastern Alps
Slavic settlement of the Eastern Alps region was a historic process that took place between the 6th and 9th century AD, having culminated in the final quarter of the 6th century. During this period, the Eastern Alps, comprising the area of modern Slovenia and large parts of modern Austria (Carinthia, Styria, East Tyrol, Lower Austria and parts of Upper Austria) were settled by Slavic tribes. This settlement meant the beginning of the ethnogenesis of the Slovene people.
Historical background 
The migration of Slavic peoples from their homeland began in roughly the late 4th to early 5th century, as Germanic peoples started moving into the territory of the Roman Empire. The migrations were stimulated by the arrival of Huns into Eastern Europe. The Germanic peoples subsequently fought for control over territories in the eastern part of the disintegrating Roman Empire. Slavic tribes were part of various tribal alliances with the Germanic (Lombards, Gepids) and Eurasian (Avar, Bulgar) peoples.
The prevailing view on the Slavic settlement of the Eastern Alps is based mostly on evidence deduced from archeological remains (many of which have been discovered only recently due to the extensive highway constructions in Slovenia), ethnographic traces (patterns of rural settlement and land cultivation,) as well as on the ascertainments of historical linguistics (including toponymy). Besides, it is fully confirmed by the relatively few available contemporary mentionings and early historical sources (such as Historia Langobardorum by Paulus Diaconus or letters from Pope Gregory I). Another important evidence of Slavic advances is the progressive decline of ancient Christian dioceses in the respective areas.
Phases of the settlement 
The first phase of Slavic settlement in the Eastern Alps region is dated around the year 550 and originated in the area of modern Moravia (i.e., the West Slavic speaking branch). From there, Slavic peoples moved southward into the territory of the former Roman province of Noricum (modern Upper and Lower Austria regions). Subsequently, they progressed along the valleys of Alpine rivers towards the Karavanke range and towards the settlement of Poetovio (modern Ptuj), where the decline of the local diocese is recorded before 577.
The second phase of Slavic settlement came from the south and took place after the retreat of Lombards into Northern Italy in 568. The Lombards contracted to cede the relinquished territory to their new allies, the Avars, who at that time were the overlords of Slavs. Avars first appeared in Europe around 560 when they reached lower Danube. In 567 the Avars and Lombards jointly defeated the Gepids. After the Lombards moved to Italy in 568, the Avars became the nominal rulers of both the Pannonian plain (which they had conquered by 582) and the adjacent Eastern Alps region. The Slavic-Avar progress towards the Eastern Alps is traceable on the basis of synodal records of the Aquileian metropolitan church which speak of the decline of ancient dioceses (Emona, Celeia, Poetovio, Aguntum, Teurnia, Virunum, Scarabantia) in the respective area. In 588 the Slavs reached the area of the Upper Sava River and in 591 they arrived to the Upper Drava region where they soon fought with the Bavarians who were led by king Tassilo I. In 592 the Bavarians won, but in 595 the Slavic-Avar army gained victory and thus consolidated the boundary between the Frankish and Avar territories. Between 599-600 the Slavs pushed through Istria and the Karst region towards Italy.
From 600 to the 8th century Slavs settled the entire Kras area up to the Friulan plain, having thus formed an ethnic boundary between the Slavic and Romance territories which has largely remained into modern days. The attempt by Slavs to penetrate westward into Friuli probably ended after they had been defeated by the Lombards at Lauriana, in 720.
Avar domination over the Slavs persisted until mid 620s. In 623 the Slavs, led by Frankish merchant Samo, rebelled against the Avars. In 626 the Avars were ultimately defeated at Constantinople, after which Samo became the ruler of the first historically known Slavic polity, Samo's Tribal Union, which persisted until his death in 658. Subsequently, a smaller Slavic principality emerged around 660, known as Carantania, and was absorbed into the Frankish Empire in 745.
Slavs and the aboriginal population 
After settling in the Eastern Alps region, Slavs subsequently subjugated the aboriginal Romanised population which had dwelt in the territory of the former Noricum province and in its cities. In late antiquity, the aboriginal population evaded Slavic settlers by moving into remote and elevated places, usually hills, where they built fortifications; such examples are Ajdna in the Karavanke mountain ridge and Rifnik near modern Celje. However, recent archeological research shows that even certain well-fortified cities in the lower areas managed to protect themselves from the invaders. Part of the aboriginal population escaped into Italy and to the cities along the Adriatic coast, among them Civitas Nova (modern Novigrad). Many aborigines were enslaved by the Slavs (an old Slavic term for slaves was krščenik, meaning a Christian, as the aborigines were Christians), some, however, assimilated with Slavs and thus enriched their culture.
Slavs referred to the Romanised aborigines as Vlahi or Lahi. Certain place names in modern Slovenia, such as Laško, Laški rovt, Lahovče, and others, bear witness to this. Also a number of river names in modern Slovenia, like Sava, Drava, Soča, as well as the geographic name Carniola (Slovenian Kranjska) were adopted from the Romanised aborigines.
- Friedrich Lotter, Rajko Bratož, Helmut Castritius, "Völkerverschiebungen im Ostalpen-Mitteldonau-Raum zwischen Antike und Mittelalter (375-600)". Berlin, New York: De Gruyter, 2003. COBISS 23545442
- Mitja Guštin, "Začetki slovanskega naseljevanja na Slovenskem" [The beginnings of Slavic settlement of the Slovene lands], Časopis za zgodovino in narodopisje = Review for History and Ethnography 75 (2004), p. 253-265. COBISS 774611
- Paulus Diaconus, "Historia Langobardorum," IV 7, 10.
- Gregorius Registrum Epistolarum 2, IX, 154; X, 15.
- Peter Štih. "Ozemlje Slovenije v zgodnjem srednjem veku: osnovne poteze zgodovinskega razvoja od začetka 6. stoletja do konca 9. stoletja" [The territory of Slovenia during early Middle Ages: a basic outline of historical development from early 6th century to late 9th century], Ljubljana, 2001. COBISS 111715072
- Peter Štih. "Slovenska zgodovina: Od prazgodovinskih kultur do konca srednjega veka. [Slovenian history: From prehistoric cultures to late Middle Ages] 
Further literature 
- Rajko Bratož, "Gli inizi dell'etnogenesi slovena : fatti, tesi e ipotesi relativi al periodo di transizione dall'eta antica al medioevo nel territorio situato tra l'Adriatico e il Danubio". In publication: La cristianizzazione degli Slavi nell'arco alpino orientale, ur. Andrea Tilatti. Nuovi studi storici, 69. Roma, Gorizia, 2005, str. 145-188. COBISS 24472109
- Bogo Grafenauer, "Naselitev Slovanov v Vzhodnih Alpah in vprašanje kontinuitete" [Slavic settlement of the Eastern Alps and the issue of continuity], Arheološki vestnik 21-22 (1970–71), p. 17-32;
- Mitja Guštin, ed., "Zgodnji Slovani: zgodnjesrednjeveška lončenina na obrobju vzhodnih Alp = Die frühen Slawen: frühmittelalterliche Keramik am Rand der Ostalpen". Ljubljana, 2002. COBISS 3411552
- Hans-Dietrich Kahl, "Der Staat der Karantanen: Fakten, Thesen und Fragen zu einer frühen slawischen Machtbildung im Ostalpenraum". Ljubljana, 2002. COBISS 3568736
- Peter Štih, "Ob naselitvi Slovanov vse pobito?" [Did Slavic settlement result in the killing of the entire population?]. In publication: Množične smrti na Slovenskem: 29. zborovanje slovenskih zgodovinarjev [Massive killings in Slovenia: 29th conference of Slovenian historians], Ljubljana, 1999, p. 79-93. COBISS 10024290
- Peter Štih, Janez Peršič, "Problem langobardske vzhodne meje" [The issue of the Lombard eastern frontier], Zgodovinski časopis = Historical Review 35 (1981), p. 333-341. COBISS 14735714
- Aleš Žužek, "Naselitev Slovanov v vzhodnoalpski prostor" [Slavic settlement of the Eastern Alps area], Zgodovinski časopis = Historical Review 61 (2007), p. 261-287.