In Espionage and Treason in Classical Greece, Gerolymatos (formerly, Simon Fraser Univ.) analyzes the development of intelligence gathering in ancient Greece, focusing mainly on proxenoi, citizens of Greek city-states who essentially served as diplomatic representatives by offering to use their privileged status to protect the interests of other city-states at home. Initially created as aides to foreign city-states, proxenoi could represent outside interests in commercial trade, religious ceremonies, and political alliances. However, due to their trusted position, many proxenoi became information gatherers and ultimately spies for the foreign city-state that employed them. These agents became well respected and well protected, not only by their foreign city-state employers but also by their home city-states. Through meticulous study of government decrees, burial placards, and other references made to the proxenoi, Gerolymatos provides many anecdotal stories of these envoys in action. Although he is quick to argue that these Greek intelligence gatherers may resemble the intelligence agents and spies of more modern times, the proxenoi of ancient Greece were not part of a formal intelligence agency. Nevertheless, this study of ancient espionage still resonates in today’s world of cyberwarfare and spying. Summing Up: Recommended. Upper-division undergraduates through faculty.