Reconstruction of Iron Age social and political structures relies initially on written sources, but classical texts are both biased in how they describe institutions, especially among other peoples, and patchy in time and space. From the mid-first millennium BC, we get details on how polities such as Athens, Sparta, and Rome functioned, but these are not representative of other Greek and Italian peoples, let alone non-Mediterranean societies. The second source of information is archaeology, especially burials, but also settlements. The chapter discusses social and political development using both a core–periphery (Mediterranean societies were more complex than those in the north) and an evolutionary model, though not one which necessarily assumes increasing complexity. The varying nature of individual power bases is also considered. A major area of contention (including between the authors) is the extent to which we can back-project documented societies into the past or into other contexts.