Chapter 2 focuses on how the formative process of global international society (GIS) over the past few centuries explains the differentiation we find both among states and within GIS. The formative process is framed in the form of two general models: polycentric (where several separate civilizational cores merge into a single international society) and monocentric (where one local civilizational core rises to dominate all the others). The monocentric model is the one that fits most closely with the expansion story, and the chapter explores four sub-models within that of how both the states and some of the other substructures of GIS came into being: unbroken creation, repopulation, colonization/decolonization, and encounter/reform. The analysis concentrates on how these models generated marked differentiations among the types of states that became members of contemporary GIS and sometimes distributed these differences in patterned ways.