The subject of this article is the tradition of world maps that illustrate Macrobius' Commentary on the Dream of Scipio in manuscripts produced before 1100. Examination of the maps in manuscript context reveals that the primary purpose of the image was to illustrate the direction of ocean flows, the formation of seas, and the relationship of the known world to unknown but hypothesized regions. The image was not static: it was adapted in several different ways—at times simplified, at others made more complex. The evidence of pre-twelfth-century manuscripts suggests that it is possible to identify sub-groups within the corpus of Macrobius maps, but that it may not be possible to establish lines of descent from the original fifth-century map.