The Darband Wall in southern Uzbekistan marks an important political border in the Classical world, yet the dating of its construction is largely relative and contested. Presenting 10 new radiocarbon dates from the wall, the authors argue that construction began in the early or middle third century BC, likely under Seleucid or early Greco-Bactrian rule, while later reconstruction efforts coincide with Kushan expansion around the first and second centuries AD. Early Hellenistic-style fortifications reveal a defensive, and possibly an orientational, shift during Kushan rule that underscores both the strategic significance of the wall and the need for more extensive investigation.