The narrow neck of land that joins the Peloponnese with the Greek mainland was central to the fortunes of the city of Corinth and the history of Greece from the classical Greek period to the end of the ancient world. Corinth was perfectly situated for monitoring land traffic between Athens and Sparta and overland movements between eastern and western seas. David Pettegrew’s book offers a new history of the Isthmus of Corinth from the Romans’ initial presence in Greece during the Hellenistic era to the epic transformations of the Empire in late antiquity. A new interpretation of the extensive literary evidence outlines how the Isthmus became the most famous land bridge of the ancient world, central to maritime interests of Corinth, and a medium for Rome’s conquest, annexation, and administration in the Greek east. A fresh synthesis of archaeological evidence and the results of a recent intensive survey on the Isthmus describe the physical development of fortifications, settlements, harbors, roads, and sanctuaries in the region. The author includes chapters on the classical background of the concept isthmos, the sacking of Corinth and the defeat of the Achaean League, colonization in the Late Roman Republic, the Emperor Nero’s canal project and its failure, the growth of Roman settlement in the territory, and the end of athletic contests at Isthmia. The Isthmus of Corinth offers a powerful case study in the ways that shifting Mediterranean worlds transformed a culturally significant landscape over the course of a millennium.