The article discusses a little-known lost Persian tale, The Story of Sharwin of Dastabay, and traces references to it in Arabic, Persian, and Byzantine sources. The earliest references to the story come from the mid- to late eighth century, and it seems to have remained well known in Arabic and Persian literature until the early twelfth and possibly the early fourteenth century, while Byzantine literature shows that at least some of its elements circulated already in the mid-sixth century. The article also discusses how the story may have been transmitted both in Iran and, crossing the linguistic boundary, in an Arabic context. Though much of the story remains unknown, it is clear that it relates to later epics and reveals something of the literary context of Firdawsi and his Shahname.