The White Croats (Croatian: Bijeli Hrvati; Polish: Biali Chorwaci; Slovak: Bieli Chorváti; Ukrainian: Білі хорвати, romanized: Bili khorvaty), also known simply as Croats, were a group of Early Slavic tribes that lived between East Slavic and West Slavic tribes in the historical region of Galicia north of the Carpathian Mountains (in modern Western Ukraine and Southeastern-Southern Poland), and in Northeastern Bohemia.
Debates continue over the origin of the Croats and related topics. Their ethnonym is usually considered to be of Iranian origin, and historians regard them one of the oldest Slavic tribes or tribal alliances that formed prior to the 6th century CE. They were an East Slavic tribe, but bordered both East Slavic groups (Dulebes and their related Buzhans and Volhynians, Tivertsi, and Ulichs) in Western Ukraine; and West Slavic tribes (Lendians and Vistulans) in southeastern Poland, controlling an important trade route from East to Central Europe. Archaeologically the Croats were mostly related to the Korchak and Luka-Raikovets cultures identified with the Sclaveni (while their connection to the Antes and to the Penkovka culture remains a matter of dispute). Their area is characterized by use of stone defenses, tiled tombs (and kurgan-like tombs), stone ovens, and many large, fortified settlements and cult buildings. They practiced Slavic paganism. Foreign medieval authors documented the Croats in historical sources and legends, and had their own origo gentis.
In the late-6th and early-7th centuries, some of the Croats migrated from their homeland, White or Great Croatia in the Carpathians, to the Roman province of Dalmatia (in present-day Croatia along the Adriatic Sea), becoming ancestors of the modern South Slavic Croats. They probably were among the Slavs who with the Pannonian Avars plundered the Roman provinces, but when settled they revolted against the Avars and soon started accepting Christianity during the time of Porga (fl. c. 7th century), the first known archon of the Duchy of Croatia. Other Croats who stayed in their Carpathian homeland continued to practise paganism and formed a tribal proto-state with the polis-like gords of Plisnesk, Stilsko, Revno, Halych, Terebovlia (among other) in Western Ukraine, which lasted until the very end of the 10th century. They were pressured and influenced by more centralized polities: Great Moravia, the Duchy of Bohemia, the Duchy of Poland, Kievan Rus' and the Principality of Hungary. After their defeat by Kievan Rus', on their territory were organized East Slavic principalities of Peremyshl, Terebovlia, Zvenyhorod and finally the Principality of Halych.
According to some modern sources, the ethnic name of White Croats was possibly preserved in parts of Western Ukraine and Southern Poland until the 19th and early-20th centuries. Historians see the northern White Croats as having become assimilated into the Ukrainian, Polish, and Czech nationalities, and as having been precursors of the Rusyns.