This work presents results of rescue excavations by The Packard Humanities Institute (PHI) at Zeugma on the Euphrates in southeastern Turkey. Fieldwork was designed to salvage parts of the ancient city that slowly disappeared from view over several months in 2000 during the gradual filling of the reservoir behind a new hydroelectric dam near Birecik. At the outset of the crisis, PHI launched an ambitious program of excavation and conservation to document the ancient city for posterity. The result was an international collaboration on a scale rarely witnessed for archaeological projects. It is no surprise that this unparalleled endeavor has produced impressive results. These volumes present the final reports of these activities.