Through philological and historical analysis focused on Gudea's slave dossier, this article elucidates the causes and mechanisms that brought Iranian slaves to early southern Mesopotamia. The slave dossier documents a brief but intensive influx of Elamite slaves to Lagash on the lower Tigris during the reign of Gudea, ca. 2130–2110 B.C., who fought the powerful polity of Anshan in Fars. The author argues that consequent political instability and economic inequality in Elam fuelled three mechanisms of slave relocation. First, royal troops brought captives. Second, the palace bought foreigners from abroad and locally. Third, royals received Iranians as gifts or tribute (“kids led by one's side”) from locals and Iranian states in areas where Gudea campaigned. Finally, locals gave their Iranian slaves back to the palace as gifts. On a theoretical level, the study distils four elements shared by all forms of slave mobility: the giver and the receiver, the economic and political relations between them that cause slave transfer, the physical and social spaces between which the transfer occurs, and the slaves and their demographic characteristics.