Several Muslim historians, such as al-Tabari and al-Mas'udi, consider the Zanj revolt to be one of the "most vicious and brutal uprisings" of the many disturbances that plagued the Abbasid central government. Modern scholars have characterized the conflict as being "one of the bloodiest and most destructive rebellions which the history of Western Asia records," while at the same time praising its coverage as being among the "most fully and extensively described campaign in the whole of early Islamic historical writing." The precise composition of the rebels remains a subject of debate, both as regards their identity and as to the proportion of slaves and free among them – available historical sources being open to various interpretations.