Early Slavs, especially Sclaveni and Antae, including the White Croats, invaded and settled the Southeastern Europe since the 6th and 7th century. It is considered that the Czech-Polish Croatian tribes were related to the Croatian tribes from Zakarpattia and Prykarpattia in Ukraine, and that they became separated during the migration period, at least by the end of the 6th and early 7th century or earlier, and seemingly formed one large Proto-Slavic tribe or tribal alliance. However, the same ethnic name does not necessarily mean all the tribes had the same origin. Their exact place of migration is uncertain, while some scholars considered it to be around Bohemia and Polabia along a Western route through the Moravian Gate, other argued to be in Lesser Poland and Western Ukraine according to historical-archaeological and linguistical data about the main movement of the Avars and Slavs, and that "served as a direct link between Eastern and Southern Slavs".