The Sanctuary of the Great Gods on the island of Samothrace was a renowned center of religious life in the eastern Mediterranean from the seventh century B.C. until the fourth century of the Christian era, and the mysteries practiced there rank in age and historical importance with those of Eleusis. Volume 10 of the records of the Samothrace excavations focuses on the elaborate Propylon dedicated by Ptolemy II, which was, from early Hellenistic times,...