The beginnings of statehood - the formation of two Croatian principalities The name Croat (Hrvat), which is probably of Iranian origin, was first mentioned in the second or third century A.D. near the Sea of Azov. From here the Croats migrated to southern Poland around Cracow, where the so-called White Croatia was located. Around the year 630 they arrived in the western part of the Balkan Peninsula. They defeated or assimilated the Illyro-Celtic tribes, which were already somewhat Romanized, freed themselves from the Avars and established two principalities, one on the territory of the former Roman province of Dalmatia, and the other in the Pannonian region.
The first principality was known as the Coastal or Dalmatian Croatia, and the other as Pannonian or Sava Croatia. In addition to these areas, the Croats also settled southern Dalmatia and the territory of today's Herzegovina and Montenegro, which historical sources refer to as Red Croatia. They also settled Bosnia, Istria and southern Hungary, but they did not maintain a strong presence in all of these peripheral territories, as they were subject to assimilation. The Roman population withdrew into the Byzantine cities on the coast or islands (e.g. Split, Zadar, Trogir, Rab, Osor, Krk), while the Illyro-Roman population withdrew to the highlands, where they later became known as Vlach stock-herders.
The Croats soon accepted Christianity, and became a part of Roman and Western Christian civilization. In 812 the Franks (under Charlemagne) and the Byzantine Empire created spheres of interest, and the Croats fell under the Franks, while the coastal cities came under the rule of Constantinople. A result of this division was the revolt of Ljudevit (Louis), the prince of Sava Croatia, against the Frankish state (818), while Borna, the prince of Coastal Croatia, supported the Franks. A genuine war broke out, in which Ljudevit repelled the Frankish armies and defeated Borna. This was how the Croats first entered the political stage of Europe with their two principalities.