The Croats trace their origins to a southwards migration of some of the Early Slavs in the 6th- and 7th-centuries CE, a tradition supported by anthropological, genetic, and ethnological studies. However, the archaeological and other historic evidence on the migration of the Slavic settlers, on the character of the native population in the present-day territory of the Croatia, and on their mutual relationships suggests diverse historical and cultural influences.
Croatian ethnogenesis The definition of Croatian ethnogenesis begins with the definition of ethnicity, according to which an ethnic group is a socially defined category of people who identify with each other based on common ancestral, social, cultural or other experience, and which shows a certain durability over the long period term of time. In the Croatian case, there is no doubt that in the Early Middle Ages a certain group identified themselves by ethnonym Hrvati (Croats), and was identified as such by the others. It also had a political connotation, it continued to expand, and since the Late Middle Ages explicitly identified with the nation, although not in the exact meaning as of the contemporary modern nation.
In the case of the present-day Croatian nation, several components or phases influenced its ethnogenesis:
the indigenous prehistoric component which dates from Stone Age, before 40,000 years, and the younger Neolithic culture like Danilo dated 4700–3900 BC, and Eneolithic culture like Vučedol dated 3000 and 2200 BC. the protohistoric component, which includes ancient people like Illyrians (including the Dalmatae and Liburnians in coastal Croatia, and the Pannonii in continental Croatia); Celtic or mixed Celtic-Illyrian people, such as the Iapodes, Taurisci and Scordisci also existed for a time in continental Croatia. In the 4th century BC there also existed a few Greek colonies on the Adriatic islands and coast. the classical antiquity component caused by the Roman conquest, which included a mixture of ancient Illyrian people and Rome's colonists and legionaries; there was also a temporary presence of Iranian-speaking Iazyges on the border of Roman Dalmatia at this time. the Late Antiquity-Early Middle Ages component from the Migration Period, started by the Huns, and which in Croatia included in the first phase Visigoths and Suebi, who didn't stay for a long period of time, and Ostrogoths, Gepids and Langobards, who formed the brief Ostrogothic Kingdom (493-553 AD). In the second phase occurred the Slavic migrations to the Balkans, often associated with the Pannonian Avars' activity. the final Middle Ages-Modern Age component, which included the presence of Magyars/Hungarians, Italians/Venetians, Germans/Saxons and others. After the 14th century, because of the black death, and the late 15th century, because of Ottoman invasion, the Croatian ethnonym expanded from the historic Croatian lands to Western Slavonia, which caused Zagreb to become capital city of the Croatian Kingdom, and to become incorporated with the population ethnogenesis of that territory. The Ottoman invasion caused many migrations of the people within the Balkans and in Croatia, like those of the Serbs and Vlachs, but the upcoming world wars and social events also influenced the Croatian ethnogenesis.
Old historical sources
The mention of the Croatian ethnonym Hrvat for a specific tribe before the 9th century is not yet completely confirmed. According to Constantine VII's work De Administrando Imperio (10th century), a group of Croats separated from the White Croats who lived in White Croatia and arrived by their own will, or were called by the Byzantine Emperor Heraclius (610–641), to Dalmatia where they fought and defeated the Avars, and eventually organized their own principality. According to the legend preserved in the work, they were led by five brothers Κλουκας (Kloukas), Λόβελος (Lobelos), Κοσέντζης (Kosentzis), Μουχλώ (Mouchlo), Χρωβάτος (Chrobatos), and two sisters Τουγά (Touga) and Βουγά (Bouga), and their archon at the time was father of Porga, and they were baptized during the rule of Porga in the 7th century. This is documented in chapter 30 and 31 of Constantine VII's work.
The old historical sources do not give an exact indication of the ethnogenesis of these early Croats. Constantine VII does not identify Croats with Slavs, nor does he point to differences between them. John Skylitzes in his work Madrid Skylitzes identified Croats and Serbs as Scythians. Nestor the Chronicler in his Primary Chronicle identified White Croats with West Slavs along Vistula river, with other Croats included in the East Slavic tribal union. The Chronicle of the Priest of Duklja identifies Croats with the Goths who remained after king Totila occupied the province of Dalmatia. Similarly, Thomas the Archdeacon in his work Historia Salonitana mentions that seven or eight tribes of nobles, which he called "Lingones", arrived from Poland and settled in Croatia under Totila's leadership.
Research history The Croatian ethnonym Hrvat, as well of those five brothers and sisters and the early ruler Porga, are often not considered to be of Slavic origin, yet again, are quite original to be a pure fabrication of Constantine VII. As such, the origin of the early Croats before and at the time of arrival to the present day Croatia, as well as their ethnonym, were an eternal topic of historiography, linguistics and archaeology. However, the theories were often elaborated in non-scientific terms, supported by specific ideological intentions, and often by political and cultural intentions of the time. This kind of interpretations caused a lot of damage to certain theories and actual scientific community. It should be taken into serious consideration whether the origin of the early Croatian tribes can be regarded also as the origin of Croatian nation, and can only be asserted that the Croats as are known today as a nation became only when Croatian tribes arrived and assimilated other populations in the territory of present-day Croatia.
Slavic theory
The Slavic theory, in extreme form also known as the Pan-Slavic theory, is the idea that the Slavs came to Illyricum from Poland dating back at least to the 12th century. With the development of Croatian historiography since the 17th century was elaborated in realistic terms, and considered Croats as one of the Slavic groups which settled in their modern-day homeland during the migration period. Constantine the VII's work was particularly researched by the 17th century historian Ivan Lučić, who concluded that the Croats came from White Croatia on the other side of the Carpathian mountains, in "Sarmatia" ("Poland", placing them in Eastern Galicia), with which historians today mostly agree upon.
In the late 19th century, the most significant impacts on future historiography was the work of Franjo Rački, and the intellectual and political circle around Josip Juraj Strossmayer. Rački's view of the unified arrival of the Croats and Serbs to the "partially empty house", fit the ideological frameworks of Yugoslavism and Pan-Slavism. The ideas by Rački were furtherly developed by historian Ferdo Šišić in his seminal work History of the Croats in the Age of the Croat Rulers (1925). The work is considered as the foundation stone for later historiography. However, in the first and second Yugoslavia, the Pan-Slavic (pure-Slavic) theory was particularly emphasized because of the political context and was the only officially accepted theory by the regime, while other theories which attributed non-Slavic origin and components were ignored and not accepted, and even their supporters, because of also political reasons, were persecuted (Milan Šufflay, Kerubin Šegvić, Ivo Pilar). The official theory also ignored some historical sources, like the account of Constantine VII, and considered that the Croats and Serbs were the same Slavic people who arrived in one and the same migration, and unwilling to consider foreign elements in those separate societies. There were Yugoslavian scholars like Ferdo Šišić and Nada Klaić who allowed limited non-Slavic origin of certain elements in Croatian ethnogenesis, but they were usually connected with the Pannonian Avars and Bulgars. The main difficulty of the Pan-Slavic theory was the Croatian ethnonym which could not be derived from the Slavic language.
The Slavic theory about the 7th century migration from Zakarpattia or Lesser Poland remains the mainstream historiographical and archaeological theory. According to extensive folklore and other studies by Radoslav Katičić, the Slavdom of the Croats is unquestionable, as well as the survival of some autochthonous elements, while the Iranian origin of their ethnonym is the least unlikely. With this conclusion also agreed other scholars like Ivo Goldstein, and John Van Antwerp Fine Jr.
Autochthonous-Slavic theory Autochthonous-Slavic theory dates back to the Croatian Renaissance, which was supported by Vinko Pribojević and Juraj Šižgorić. There's no doubt that the Croatian language belongs to the Slavic languages, but they considered that Slavs were autochthonous in Illyricum and their ancestors were old Illyrians. It developed among the Dalmatian humanists, and was also considered by early modern writers, like Matija Petar Katančić, Mavro Orbini and Pavao Ritter Vitezović. This cultural and romanticist idea was especially promoted by the national Illyrian Movement and their leader Ljudevit Gaj in the 19th century.
According to the autochthonous model, the Slavs homeland was in the area of former Yugoslavia, and they spread northwards and westwards rather than the other way round, which is "completely untenable". A revision of the theory, developed by Ivan Mužić in 1989, argues that Slavic migration from the north did happen, but the actual number of Slavic settlers was small and that the autochthonous ethnic substratum was prevalent in the formation of the Croats, but that contradicts and does not answer the presence of a predominant Slavic language, The social and linguistical situation of the pre-Slavic population is hard to reconstruct, especially if one accepts the theory that the autochthonous population was dominant at the time of the arrival of the Slavs yet accepted the language and culture of Slavic newcomers who were in the minority. The assumptions that the Illyrians were an ethnolinguistic homogeneous entity were rejected in the 20th century, and according to the scholars who support the Danube basin hypothesis of the Slavic homeland, it is considered that some proto-Slavic tribes existed even before the Slavic migration to Southeastern Europe. However, this theory has been scientifically discredited and rejected, having an Anti-Slavic sentiment.
Constructionist late-migration theory