sentences:  As such, the arrival of the Croats was seen as a second wave of Slavic migrations, which took over Dalmatia from Avar hegemony.However, as early as the 1970s, scholars questioned the reliability of Porphyrogenitus' work, written as it was in the 10th century.Rather than being an accurate historical account, "De Administrando Imperio" more accurately reflects the political situation during the 10th century.