The history of Slovenia chronicles the period of the Slovenian territory from the 5th century BC to the present. In the Early Bronze Age, Proto-Illyrian tribes settled an area stretching from present-day Albania to the city of Trieste. The Slovenian territory was part of the Roman Empire, and it was devastated by the Migration Period's incursions during late Antiquity and the Early Middle Ages. The main route from the Pannonian plain to Italy ran through present-day Slovenia. Alpine Slavs, ancestors of modern-day Slovenians, settled the area in the late 6th Century AD. The Holy Roman Empire controlled the land for nearly 1,000 years. Between the mid-14th century through 1918 most of Slovenia was under Habsburg rule. In 1918, most Slovene territory became part of the Kingdom of Serbs, Croats, and Slovenes, and in 1929 the Drava Banovina was created within the Kingdom of Yugoslavia with its capital in Ljubljana, corresponding to Slovenian-majority territories within the state. The Socialist Republic of Slovenia was created in 1945 as part of federal Yugoslavia. Slovenia gained its independence from Yugoslavia in June 1991, and today it is a member of the European Union and NATO.
Prehistory to Slavic settlement
The area later known as Slovenia has been inhabited since prehistoric times. There is evidence of human habitation from ~250,000 years ago.
The best-known Neanderthal archaeological site in Slovenia is a cave close to the village of Šebrelje near Cerkno, known as Divje Babe. Here the Divje Babe flute was found in 1995, a perforated bone controversially believed to be a flute. It is believed to date from 41000 ± 700 BC. It is possibly the world's oldest known musical instrument.
In 2002, remains of pile dwellings over 4,500 years old were discovered in the Ljubljana Marsh, later protected as a UNESCO World Heritage Site, along with the Ljubljana Marshes Wooden Wheel, the oldest wooden wheel in the world. It indicates that wooden wheels appeared almost simultaneously in Mesopotamia and Europe. In the 1920s and 1930s, Cro-Magnon artifacts such as pierced bones, bone points, and a needle were found n Potok Cave.
In the transition period between the Bronze Age to the Iron Age, the Urnfield culture flourished. Archeological remains dating from the Hallstatt period were found particularly in southeastern Slovenia, with important settlements in Most na Soči, Vače, and Šentvid pri Stični, including situlas in Novo Mesto, the "Town of Situlas".
In the Iron Age, present-day Slovenia was inhabited by Illyrian and Celtic tribes until the 1st century BC, when the Romans conquered the region
During Roman times, the area was divided between Venetia et Histria (region X of Roman Italia in the classification of Augustus) and the imperial provinces Pannonia and Noricum. The Romans established strategic urban posts at Emona (Ljubljana), Poetovio (Ptuj), and Celeia (Celje); and constructed trade and military roads to connect Italy with Pannonia. Important Roman towns there included Emona, Celeia and Poetovio. Other important settlements were Nauportus, Neviodunum, Haliaetum, Atrans, and Stridon.
In 394, the historic Battle of the Frigidus took place in the Vipava Valley, where Eastern Emperor Theodosius I defeated German usurper Eugenius. As the western empire weakened through the 5th and 6th centuries, the area was subject to invasions by the Huns and Germanic tribes during their incursions into Italy. To protect the Italian heartland the Romans built the Claustra Alpium Iuliarum (defensive line of towers and walls).
During the Migration Period (4th-9th century), the region suffered many barbarian invasions, due to its strategic position as the main passage from the Pannonian Plain to the Italian Peninsula. Rome abandoned the region at the end of the 4th century. Most cities were destroyed, while the remaining local population moved to the highland areas, establishing fortified towns. In the 5th century, the region was part of the Ostrogothic Kingdom, and was later contested between the Ostrogoths, the Byzantine Empire and the Lombards.
The Slavic tribes migrated to the Alpine area after the westward departure of the Lombards (the last Germanic tribe) in 568, and, under intense pressure from Avars, established a Slavic settlement in the Eastern Alps. They came from two directions, North (via today's East Austria and Czech Republic), settling around today's Carinthia and west Styria, and South (via today's Slavonia), settling around what became central Slovenia and became known as the Alpine Slavs.
From 623 to 624 or possibly 626 onwards, King Samo united the Alpine and Western Slavs against both the Avars and Germanic peoples and established what is referred to as Samo's Kingdom. Following Samo's death around 658, they formed independent geopolitical entities: duchy of Carantania, and Carniola, later duchy Carniola. While the Avars temporarily reclaimed surrounding territories, Frankish King Charlemagne decisively defeated them in 803, bringing the entire region under Western European influence.
In 745, Carantania and the rest of Slavic-populated territories, being pressured by newly consolidated Avar power, submitted to Bavarian overrule and were, together with the Duchy of Bavaria, incorporated into the Carolingian Empire. The Carantanians, particularly the Carinthian Slovenes, were the first Slavic people to accept Christianity. They were mostly Christianized by Irish missionaries, among them Modestus, known as the "Apostle of Carantanians". The eastern part of Carantania was ruled again by Avars between 745 and 795.
Carniola, too, came under the Franks, and was Christianized from Aquileia. Following the anti-Frankish rebellion of Liudewit in 818, the Franks removed the Carantanian princes, replacing them with their own border dukes. Consequently, the Frankish feudal system reached the Slovene territory. Under Emperor Arnulf of Carinthia, Carantania, briefly emerged as a regional power, but was destroyed by the Hungarian invasions in the late 9th century.
Carantania-Carinthia rose again as an autonomous administrative unit in 976, when Emperor Otto I, "the Great", after deposing the Duke of Bavaria, Henry II, "the Quarreller", split the lands held by him and made Carinthia the sixth duchy of the Holy Roman Empire in 976, but old Carantania never developed into a unified realm.
In the late 10th and beginning of the 11th century, primarily because of the Hungarian threat, the southeastern border region of the German Empire was organized into so-called "marks" that organized the development of the Carniola, the Styria and the western Goriška/Gorizia. This consolidation and formation continued into the 14th century, led by feudal families such as the Dukes of Spanheim, the Counts of Gorizia, the Counts of Celje and finally the House of Habsburg.
Slovenes as a distinct ethnic group
The first mentions of a common Slovene ethnic identity, transcending regional boundaries, date from the 16th century.