The question of Visigothic slavery has generally been treated in the context of larger studies on the Visigoths or of the Mediterranean economy rather than studies devoted to slavery. Even when it has been examined as a thing unto itself, it has tended to get folded into larger narratives of the development of social relations in the early Middle Ages. Marxist historians, such as Abilio Barbero, Marcelo Vigil, and Chris Wickham, have attempted to fit the evidence into a historical materialist narrative that posits a decline of slavery and slaveholding in the post-Roman world as states contracted and serfs or peasants replaced slaves as the primary agricultural producers. This narrative has been countered by French social historians, especially Georges Duby and Pierre Bonnassie, who argued that slavery continued to predominate in the early medieval West, giving way to serfdom only in the tenth century.