The Pan-Slavic concept of Yugoslavia emerged in late 17th-century Croatia, at the time part of the Habsburg monarchy, and gained prominence through the 19th-century Illyrian movement.

[2] Another name popular in the early modern period was Illyrians, using the name of a pre-Slavic Balkan people, a name first adopted by Dalmatian intellectuals in the late 15th century to refer to South Slavic lands and population.

[citation needed] The Proto-Slavic homeland is the postulated area of Slavic settlement in Central and Eastern Europe during the first millennium AD, with its precise location debated by archaeologists, ethnographers and historians.

[5] None of the proposed homelands reaches the Volga River in the east, over the Dinaric Alps in the southwest or the Balkan Mountains in the south, or past Bohemia in the west.

[6] Traditionally, scholars place it in the marshes of Ukraine, or alternatively between the Bug and the Dnieper;[7] however, according to F. Curta, the homeland of the southern Slavs mentioned by 6th-century writers was just north of the Lower Danube.

[11] They were portrayed by Procopius as unusually tall and strong, of dark skin and "reddish" hair (neither blond nor black), leading a primitive life and living in scattered huts, often changing their residence.

[12] While archaeological evidence for a large-scale migration is lacking, most present-day historians claim that Slavs invaded and settled the Balkans in the 6th and 7th centuries.

[16] From the Danube, the Slavs commenced raiding the Byzantine Empire on an annual basis from the 520s, spreading destruction, taking loot and herds of cattle, seizing prisoners and capturing fortresses.

This meant that even numerically small, disorganised early Slavic raids were capable of causing much disruption, but could not capture the larger, fortified cities.

[14] The first Slavic raid south of the Danube was recorded by Procopius, who mentions an attack of the Antes, "who dwell close to the Sclaveni", probably in 518.

[18] Throughout the 6th century, Slavs raided and plundered deep into the Balkans, from Dalmatia to Greece and Thrace, and were also at times recruited as Byzantine mercenaries, fighting the Ostrogoths.

Seventh-century archaeological sites show earlier hamlet-collections evolving into larger communities with differentiated zones for public feasts, craftmanship, etc.

[32] Subsequent information about Slavs' interaction with the Greeks and early Slavic states comes from the 10th-century text De Administrando Imperio (DAI) written by Byzantine Emperor Constantine VII Porphyrogenitus, from the 7th-century compilations of the Miracles of Saint Demetrius (MSD) and from the History by Theophylact Simocatta (c. 630).

[citation needed] By 700 AD, Slavs had settled in most of Central and Southeast Europe, from Austria even down to the Peloponnese of Greece, and from the Adriatic to the Black Sea, with the exception of the coastal areas and certain mountainous regions of the Greek peninsula.

[31] Traditional historiography, based on DAI, holds that the migration of Serbs and Croats to the Balkans was part of a second Slavic wave, placed during Heraclius' reign.

[37] In 863 to Christianized Great Moravia were sent two Byzantine brothers monks Saints Cyril and Methodius, Slavs from Thessaloniki on missionary work.

[43] The Bogomil sect, derived from Manichaeism, was deemed heretical, but managed to spread from Bulgaria to Bosnia (where it gained a foothold),[44] and France (Cathars).

[45] Dalmatia, now applied to the narrow strip with Byzantine towns, came under the Patriarchate of Constantinople, while the Croatian state remained pagan until Christianization during the reign of Charlemagne, after which religious allegiance was to Rome.

[citation needed] Through Islamization, communities of Slavic Muslims emerged, which survive until today in Bosnia, south Serbia, North Macedonia, and Bulgaria.

It comprises, from west to east, the official languages of Slovenia, Croatia, Bosnia and Herzegovina, Montenegro, Serbia, North Macedonia, and Bulgaria.

South Slavic standard languages are: West: Serbo-Croatian (pluricentric) (Serbian, Croatian, Bosnian, Montenegrin) Slovene East: Bulgarian Macedonian

In southeastern Serbia, dialects enter a transitional zone with Bulgarian and Macedonian, with features of both groups, and are commonly called Torlakian.

[citation needed] According to the 2013 autosomal IBD survey "of recent genealogical ancestry over the past 3,000 years at a continental scale", the speakers of Serbo-Croatian language share a very high number of common ancestors dated to the migration period approximately 1,500 years ago with Poland and Romania-Bulgaria cluster among others in Eastern Europe.

[57] The 2006 Y-DNA study results "suggest that the Slavic expansion started from the territory of present-day Ukraine, thus supporting the hypothesis that places the earliest known homeland of Slavs in the basin of the middle Dnieper".