Questions of the origin of Croats and the time and circumstances of their migration and settlement in the former Roman province of Dalmatia have been in the very centre of interest of Croatian medieval studies for long, and still today can provoke heated discussions. Written sources that serve as bases for such discussions are, however, scarce, often indirect, and even mutually controversial. Notwithstanding, the still most widely accepted thesis is the one which dates the arrival of the Croats to Roman Dalmatia to the first half of the seventh century, relying on the only one source – the three centuries later treatise De administrando imperio. Given the lack of written data, archaeological sources are often used to corroborate this dating, specifically cremation burials in urns labelled as Slavic, as well as certain other finds. The present paper first presents the extant written sources, and then discusses precisely these archaeological ones. The cremation graves are analyzed in their closer contexts, especially regarding their dating and relations to the inhumation graves present at the same sites. Afterwards they are put in a wider context, together with other finds usually dated to the seventh and early eighth centuries, and compared with Late Antique cemeteries of the sixth and early seventh centuries. The analysis shows that cremation graves present a novelty in the region, as do also the grave-goods and burial customs in the eighth-century cemeteries. It also shows that there is no continuity between those cemeteries and the earlier ones. Still, the dating of the cremation graves and the earliest so-called Slavic pottery remains uncertain, and for now there is no firm evidence for its positioning to the period earlier than the late seventh century. In the end, it can be concluded that immigration of new populations did occur through the seventh century, but the simultaneous arrival of the Croats remains impossible to prove.