This chapter provides the historical and scholarly context to the book’s main argument, and hence treats the military and economic developments that engulfed the Greek world in the late Classical and early Hellenistic periods. arguing that these should be seen as intrinsically connected. Following discussion of scholarly approaches to the economic transformation of the Greek world at this time, paying special attention to the old formalist–substantivist debate, the chapter advocates a closer look at the types of markets available, especially the market for labour. This market, the book contends, first appeared in a full form in the military sphere; accordingly, the chapter questions scholarly approaches and attitudes towards paid military service, debating especially the notion of ‘mercenary’ soldiers, who should better be conceived of as military wage labourers.