The avowed purpose of this volume is to replace Greek Federal States, J. Larsen's 1968 landmark survey of one of the most important developments in political organisation in the Ancient World – the widespread tendency for political communities to combine under the umbrella of a unified ethnic identity, pooling legislative powers as well as economic and military resources. This tendency has in fact been the focus of a remarkable volume of scholarly endeavour in recent years, and not just in relation to the Boeotian, Achaean and Aetolian Leagues, the federal super-states of the late Classical and Hellenistic periods. It is not surprising, therefore, that the time seems ripe for a new synthesis of the results of these studies, and the success and utility of the Copenhagen Polis Project's Inventory of Archaic and Classical Poleis has arguably made the creation of a collection of up-to-date accounts of federations a pressing need for Greek historians.

This volume, edited by B. and F., two of those scholars who have been most active in the field, is in general a serviceable replacement for Larsen as a survey of the different regional forms of federalisation in the Greek world. In the introduction (pp. 1–29), the editors provide a useful summary of the historical development of scholarship on Greek federations, as part of a wider thematic discussion of the complex reality of this phenomenon, described variously by a range of different overlapping terms in the ancient sources (including koinon, ethnos, sympoliteia). Noting that concepts of statehood are themselves historically contingent and constituted within particular state systems, the editors quite sensibly avoid giving an overly prescriptive definition of federalism. Instead they work with a conception that allows for historical comparison, of federalism as a ‘principle that cuts across the dividing lines of history’ which ‘indicates that the traditional boundaries between the inside and outside of a state are somewhat yielding’ and by which member states ‘subscribe to a design that extends this dichotomy through the creation of an intermediary’ (p. 2). This understanding of federal states in the ancient world as intermediary units enables a more sophisticated approach to the wide diversity of federal phenomena visible in the Greek world, in particular to the quite different federalising trajectories of koina established by already institutionally developed poleis, koina that developed out of ethnic identity groups which themselves played an important role in the institutional crystallisation of constituent political communities and koina instituted or used by external powers.

The central sequence of chapter-length studies of particular federal states are mostly written by well-established experts of the regions concerned. Although this makes for a certain amount of summarising of views expressed by authors elsewhere, the result is a series of concise, up-to-date accounts which will rightly serve as the go-to reference for those unfamiliar with the history and institutions of federalising activity in a particular region. Minor and poorly attested federal organisations, either omitted from Larsen's work or afforded minimal attention by him, are in general well treated in the framework of this book, including the island leagues of Keos and Mytilene (treated by K. Buraselis, pp. 358–76, along with the wider Nesiotic League), the Cretan koinon (A. Chaniotis, pp. 377–85), the Dorian and Oetaean Leagues (D. Rousset, pp. 222–30) and the Italiote League (M. Fronda, pp. 386–402). By comparison, the chapters on the more major and better attested federations, such as the Boeotian (B. and A. Ganter, pp. 132–57), Aetolian (F., pp. 86–117), or Achaean (A. Rizakis, pp. 118–31) Leagues, which made up the bulk of Larsen's volume, are inevitably more compressed. For the most part they perform the balancing act between institutional detail and historical narrative reasonably well within the limited space they are allotted – and here, in any case, readers are likely to be quicker to reach for the other, more comprehensive, recent accounts which are available.

Collectively, these studies paint a rich picture of the extraordinary diversity of forms of federalism with which the Greek states experimented during their long histories, evident in widely differing degrees of federal institutionalisation and the different balances which were struck between central federal structures and their constituent political communities in terms of identity and political authority. The highly developed, centralised federal administrative structures of the Chalcidians and Boeotians, for example, provide a marked contrast with the Cretan koinon, which, as A. Chaniotis shows, lacked even the concept of dual citizenship (that is, a shared federal citizenship in addition to local citizenship), which was central to the approach of much of the twentieth-century scholarship on federalism. This volume even includes studies, like J. Roy's excellent chapter on Elis (pp. 269–84), which, in showing that federal structures cannot be identified for a particular case, demonstrate the heuristic value and limits of the concept of federalism as applied to antiquity and the importance of the wider context of interstate relations in which federal structures came into existence. This wider context is also explored in a series of chapters on other comparable interstate institutions, on wider structures of Hellenic identity (L. Mitchell, pp. 49–65, and B. Smarczyk, pp. 452–70) as well as other kinds of military alliance, including the Delian and Peloponnesian Leagues and Second Athenian League (K. Raaflaub, pp. 434–51).

The central case study chapters engage to differing extents with a number of themes identified by the editors, the most prominent of which is ethnicity. One of the central arguments for the creation of this book now is the realisation in relatively recent scholarship that the importance of ethnic identity is as a contemporary construct more than as a historical or linguistic fact. In Chapter 2 there is a good discussion by J. Hall of this issue (pp. 30–48), and the problem that still remains of understanding the precise relationship between the construction of ethnic identity and institutional structures, and this acts as a second introduction to the subsequent studies. Later studies engage with this issue to varying degrees, depending in part on the material available (in particular there are some interesting but cursory remarks in J. McInnerny's chapter on Phocis, pp. 199–221, which relate ethno-genesis to peer polity interaction). The book also includes useful accounts of the economic importance and impact of federations (E. Mackil, pp. 487–502), and federalism in ancient political theory (C. Bearzot, pp. 503–11) and its modern reception (G.A. Lehmann, pp. 512–23).

The obvious point of comparison for this volume is the Inventory of Archaic and Classical Poleis, which works with a much more tightly prescribed definition of the object under study (the polis), and the information to be given in the entry for each political community. The approach taken by this book project, of dividing the material between contributors who have been allowed a substantial amount of latitude in the particular shape of their contributions, has resulted in a generally useful book in a surprisingly short period of time. There are, however, some troubling absences – the almost complete omission of the koina of the Triphylians, Perrhaebians and Aenianians, which are mentioned once or twice in this volume but not examined in any detail, despite the fact that we possess clearer evidence for their institutional arrangement than for others examined more speculatively here. It is also less easy than it might have been to compare the evidence of federal characteristics positively attested for different communities. A better set of indexes might have helped to remedy this partially. Cross-references within the volume are also thin on the ground and lack page numbers.