The introduction highlights the two observations that underlie the book: first, a major feature of the intense power struggles that characterized the formation of the Hellenistic states was the foundation of massive urban centers; and, second, these city foundations were almost all synoikisms, the merger of smaller poleis or communities into a single city. This involved major settlement and population shifts and the reorganization, consolidation, or elimination of autonomous polities. The introduction then sketches the main problems the book addresses: the critical role that manipulating urban networks played in the creation and maintenance of large territorial kingdoms and the challenges that this forced consolidation of diverse city-state cultures presented the discrete civic, cultic, and ethnic identities of the groups forced to join these unions. It argues that this approach elucidates how the power of the kings depended on complex negotiations with cities, as well as how the traditional institutions of the Greek polis imposed limits on the authority and opportunism of the kings. At the same time, it engages the question of comparative imperial structures, exploring how this focus on centralization differentiates the Hellenistic kingdoms from other ancient empires that tended to rule through political fragmentation.