Few topics of Graeco-Roman antiquity have produced such a huge bibliography as the Roman imperial cult. After P. Herz's conspicuous bibliographic survey of 1978 covering the period from 1955 to 1975 (ANRW II.16.2) monographs and articles have continued to appear at a constant pace. This is due to the great diffusion of emperor worship and to its significant impact on the political and social realms in addition to its often ambiguous and highly debated religious connotations. Far from being merely a further addition to an already rich bibliography on imperial cult, L.'s study represents a commendable attempt at a synthesis on the subject. To adopt such an overall perspective towards the imperial cult is made difficult by another important characteristic of this phenomenon, namely the variety of forms it assumed throughout the Graeco-Roman Empire. This aspect has only recently been fully acknowledged in the scholarly debate on emperor worship (M. Beard, J. North, S. Price, Religions of Rome [1998], vol 1, p. 318: ‘There was no such thing as “the imperial cult”; rather there was a series of different cults sharing a common focus in the worship of the emperor, his family or predecessors, but … operating quite differently according to a variety of different local circumstances’; cf. also S.J. Friesen, Twice Neokoros [1993], p. 145). Any attempt at a synthesis must take into consideration this complex variety of cults pertaining to the emperors and their families as well as the different levels involved: Rome, i.e. state cult, vs the rest of the empire; provinces vs local communities, and among the latter the Roman cities (coloniae and municipia) vs the peregrine communities; finally, at a more general level, western provinces vs eastern provinces.

The idea of an opposition between West and East in the worship of the emperors, which has too often been repeated without the necessary documentary evidence, has finally been questioned. Notably, I. Gradel (ThesCRA II [2004], pp. 190–3) has argued that the cults of the living emperor were predominant at provincial and local level both in the West and in the East of the empire, the only exception being the state cult performed at Rome (and in the Roman army), which was reserved for the Divi (see also D. Fishwick, ICLW [2004], vol. 3.3, pp. 361–6; M. Beard, J. North, S. Price, Religions of Rome [1998], vol. 1, p. 349).

The perspective adopted by L. for his study on the imperial cult is also in a sense (albeit partially) unitary, but it goes in the opposite direction. While acknowledging that the emperor was invested with a superior auctoritas derived from the gods’ protection, which placed him ‘tra umano e divino’, L. argues that he was not a god in contrast to the opinion expressed by M. Clauss (Kaiser und Gott [1999]). The princeps was at the centre of a series of cultic acts, yet these were not addressed directly to him but had rather him as the main beneficiary. The sacred rituals were thus for the emperor rather than to the emperor. This was the case in the state cult but also in the provinces, in local communities and even in private rituals, especially in Italy (and the western provinces). L. devotes a great part of the study to demonstrate that, even in cases in which particular expressions such as aedes Augusti may suggest a direct cult, in reality the object of ritual practices was most likely the genius (or the numen) of the reigning emperor. Similarly, libations and sacrifices were usually performed to the gods so that they would bring favour to the emperor. In this regard L. agrees with Fishwick's interpretation according to which in the presence of a ‘double dative’ – of a god and the emperor – the second should be intended ‘as “for” rather than “to”’ (D. Fishwick, ICLW [1990], vol. 2.1, p. 440; see also D. Fishwick, ZPE 80 [1990]). A significant example is given by the interpretation of a passage in the feriale Cumanum, which prescribes a cruel sacrifice to Augustus on his dies natalis (23 September) (Inscr. It. XIII.2, no. 44, l. 3: Immolatio Caesari hostia). Given the absence of similar cases in Italy, L. suggests that this sacrifice was directed to the genius of Augustus and that the dative Caesari means ‘for’ Augustus rather than ‘to’ Augustus (cf. J. Scheid, CCG 21 [2010], 290–1).

L.'s reasoning, based as it is on a skilful and sound interpretation of the sources, is generally convincing; yet his analysis relies heavily on the evidence from Rome and Italy, which occupies two thirds of the book, while emperor cults in the provinces, especially in the Hellenophone areas, are dealt with much more concisely. However, this is partly due to the impossibility, as stated by L., to take into account the great complexity of local situations. More importantly, this ‘Romano-Italic’ connotation directly derives from L.'s deliberate choice to put at the core of his study the intentions and directives of the central power (p. 159: ‘almeno dal punto di vista del potere imperiale, non fu mai richiesto un culto diretto dell'imperatore vivente, neppure nelle province orientali’). Indeed, while he argues that in Rome, Italy and the Latinophone provinces the living emperor was not directly worshipped, L. acknowledges that in the Greek East, especially at the local level, the reigning emperor in some cases was worshipped like a god. According to L. this difference is attributable to a ‘communication gap’ between central power and Hellenophone subjects (in this regard, one could also think of different – and only partially overlapping – interests in the celebration of emperor worship).

Be as it may, a ‘system of exchange’ between imperial power and the provincial elites was at play both in the West and in the East (S. Price, Rituals and Power [1984], pp. 66–77), and it produced a substantial amount of ambiguity within emperor worship. This ambiguity is more detectable in the Hellenophone provinces due to the contraposition between the official rules of Roman state religion and the traditional disposition of Greeks to recognise a superhuman aura and divine honours to those individuals who detained (great) power especially since the Hellenistic period onwards. Significantly, in the epilogue L. focuses on ambiguity as one of the main features of the imperial cult.

Though largely conducted from the perspective of Rome and the West, L.'s study offers a valuable synthesis of Roman imperial cults, which remains a solid starting point for any interpretation of emperor worship at both local and provincial level.