Many studies have been devoted to the mosaic of the Great Palace peristyle in Constantinople / İstanbul. To its style, influences and models, as well as to its dating or to the function of the room it decorated. But there is one element that has so far not aroused much interest: the peopled scroll that circumscribes the central panel. The iconographic, chromatic, and technical richness of this border make it much more than a simple ornamental frame. It is even a key element of the pavement. This type of border developed towards the end of the 2nd century AD in workshops on the Levantine coast on the basis of a Hellenistic pattern. The presence of foliate heads at regular intervals in the border contributed to the revival of this pattern inherited from the Greek world. Four heads of this type are partially preserved in the Great Palace Mosaic. But what is it really about? The analysis of the corpus of the Roman foliate heads and the contextualising of this pavement allow to specify the origin and meaning of these heads, but also to confirm the dating of the 6th century AD, and to shed new light on the interpretation of the decorative program.