This paper examines the military virtues of the sling within the context of organized classical warfare, by considering the formation of a unit of Rhodian slingers in Xenophon's Anabasis 3.3. Because the slinger unit is created mid-campaign, it is possible to identify specific military needs faced by the Ten Thousand that required the reassignment of the Rhodians to a specialized light-armed unit. These circumstances demonstrate clearly the tactical value of light-armed troops, and this corroborates the specific military virtues that Xenophon describes. Xenophon's comparisons with the abilities of Persian and Cretan bowmen (3.3.15–17) are instructive and to be trusted: the simple weapon regularly proved itself more effective than bows and arrows, for reasons that can be described. Slings represent a technology that was used from the Bronze Age to the Roman period, to achieve specific military outcomes; significantly, slings continued to prove effective despite other technological developments in armour and tactics. The formation of the unit emerges because of geographical features of the land through which the Greeks travel and the resulting nature of skirmish-based conflict (Kelly, ABSA2012, considers how Cretan slingers were also landscape-responsive, while also discussing the psychological impacts that slingers could create). The unit's identity, however, is presented in terms of ethnic origin, and this provides both a mechanism for creating unit cohesion, and an identity that perpetuates it, even when slingers are dispersed through the ranks (3.4.15 δ ι α τ α χ θ έ ν τ ε ς). Unit cohesion is established and maintained by tactical need, technological efficiency, and ethnic identity. By focalizing discussion through the unit Rhodian slingers in Xenophon, it is possible to describe why the specialized unit was needed and the effect it had on the campaign Xenophon describes.