Recent research has demonstrated the significance for theatre history of the performances that took place at Dionysia in the demes of Attica. This article analyses the latest addition to our evidence, an honorific decree (I.Rhamnous 402), first published in 2020. The decree was passed by the Marathonian Tetrapolis, but the stele on which it was inscribed was discovered at Rhamnous. From this we learn of a Dionysia with performances of tragedy that was held by the Tetrapolis in the second half of the fourth century. We begin with a commentary that situates the decree in the wider practices of a theatre-based honorific economy common to the demes and tribes of Attica (I); and go on to discuss the puzzle of its context of discovery and the puzzle of its content, arguing that the inscription attests for the first time a Dionysia held by a corporate body larger than a single deme (II). We proceed to integrate this evidence within the existing body of knowledge of the cult of Dionysos in the Tetrapolis, making some suggestions about the likely location of the Dionysion and theatre (III). Finally, we consider the absence of the cult of Dionysos from the surviving sections of the Tetrapolis Calendar (SEG L 168). We conclude that the Dionysia probably appeared in the lost section that detailed cults at the Tetrapolis level which took place in the winter months; and further, that the mysterious entry for Marathon in Posideon (A.II.7–10) may in some way reflect the significant involvement of that deme in the Dionysia of the association (IV).
