Due to the general acceptance of oral poetry theory, Homeric metaphors have generally been regarded as formulaic set pieces with little or no contextual meaning and have correspondingly received little attention. This paper aims to demonstrate that metaphors in Homer can nevertheless fulfil cognitive functions in their respective contexts by the analysis, as an exemplary case, of a unique metaphor of death: in Il. 11.234–247 it is narrated that the Trojan Iphidamas is killed by Agamemnon and “sleeps the brazen slumber” (Il. 11.241). The metaphorical representation of death as a kind of falling asleep is an instantiation of the well-known conceptual metaphor death is sleep, while the description of the sleep of death as “brazen” permits several interpretations which all highlight the pathos of the killing and make the death of Iphidamas appear premature and regrettable. A comparison with two passages in Vergil’s Aeneid which adapt the phrasing “iron sleep” (Aen. 10.745–746; 12.309–310) indicates that the Homeric metaphor is particularly well suited to its context and contributes to the effect of the passage.