Michael Koortbojian has produced a book which like Paul Zanker's Power of Images in the Age of Augustus (1988) challenges the reader to think as much visually as textually, and offers us an image of an early Principate in which ways to present the ruler and his forbears — primarily Caesar and Augustus — changed. K. shows clearly how the phenomenon of imperial cult both was influenced by, and had influence on, many levels of ancient society in and across the Empire, and how key distinctions, such as that between private and public, affected what forms of representation occurred.

Spencer Cole (Cicero and the Rise of Deification at Rome (2013)) has recently discussed how Cicero over the course of his career confronted, used and accommodated the idea of the godlike-man with a necessary emphasis on the textual. K. is fascinated by the problems, once Roman politicians had taken the decision to turn men into gods, of representing the new divinities in a Roman context that had no clear precedents for dealing with apotheosis. The two works together enable us to appreciate more fully the intellectual and practical problems posed by deifying Caesar.

K. provides the most nuanced reading of Cicero's controversial comments (Phil. 2.110) on the honours voted to Caesar during his lifetime, denying that they conferred either a present or future divinization. Many will disagree on this, but K. lays out in exemplary fashion the difference between decreeing honours and formally setting up cult. For K., the latter job began in 42 b.c., but even between the triumvirs' decision and the final dedication of the temple to Divus Iulius in 29, there was extensive experimentation, as the new god's representation and function was being fashioned.

Denarii struck in 36 b.c. offer two different forms of future cult-image, one in which Divus Iulius appears capite velato, the other in which he is semi-nude, wearing a so-called hipmantle. In both, however, he holds a lituus. K. establishes that this symbolizes the holder's legitimate possession of imperium rather than the office of augur, an important claim to make in the hotly contested triumviral period when Caesar's legacy was still a very live issue. However, in the image that predominated under the early Principate, the lituus disappeared and the hipmantle became the key distinguishing feature of the divine iconography. K. draws out well how this form was carefully chosen to evoke Quirinus and the Genius Populi Romani. Caesar's assimilation to Romulus was being pushed during Caesar's dictatorship: now Divus Iulius could be seen as optimus augur, conditor and pater.

From an analysis of the surviving types of Caesarian portraiture, categorized as Tusculum and Pisa/Chiaramonti, K. shows that the latter was developed to represent Divus Iulius as opposed to the human Caesar. Honorific statues to Caesar granted during 45 and 44 featured a crown, probably the corona graminea, but no extant statue of Divus Iulius reveals any traces of a crown, or even of the star that Augustus records in De vita sua (Plin., HN 2.94) he had affixed to the statue of Caesar that he consecrated in the forum and which is celebrated on denarii from 17 b.c. (RIC I² 73, no. 141). If stars were a continuing part of the sculptural representation, perhaps they were metallic attachments, but no holes appear. K concludes plausibly that there was a deliberate reorientation of Caesar's imagery by Augustus (128).

In ch. 6, K. confronts the oft-held idea that divi were essentially impotent: immediately after his assassination the people of Rome worshipped him, Valerius Maximus (praef.) hails the new alacritas that the cult of Divus Iulius (and Augustus) brought to the Roman state religion and presents the foundation myth of his cult (1.8.8). Divus Iulius was propitius in the bringing of victory, his beneficium to the populus Romanus. In the immediate aftermath of his defeat of M. Antonius, Octavian claimed for himself the glory of bringing victory, seen most strikingly in a denarius (RIC I² 60, no. 270) on which (like Jupiter) he proffers a victoriola, but after the final settlement of his powers, secure in his control of the Roman world, Augustus transferred that rôle to Divus Iulius (RIC I² 74, no. 415).

In ch. 7, K.'s focus turns more to the ways, both human and ‘divine’, in which Augustus was honoured during his reign. K. brings to the fore more clearly than Ittai Gradel (Emperor Worship and Roman Religion (2002)) the dynamic and varied nature of worship offered to Augustus by individuals and communities across Italy that evolved in the absence of guidance from the centre; the complex distinction between public and private that runs through his analysis reinforces the distinction between Rome and the rest. K. helpfully illuminates notions such as numen Augustum which emerged as part of the on-going negotiation of what having human rulers who became (or would become) gods meant.

Ch. 8 highlights the difference between the sculptural representations of Divus Iulius and Divus Augustus, the latter predominately, in ‘official’ representations, fully-clothed, togate and with a radiate crown. The hipmantled Divus Julius, now fully assimilated into his divine rôle, offered a style that was widely adopted by municipal worthies from the mid-first century a.d.; eventually all specific reference to Divus Iulius was forgotten and the hipmantle merely became a conventional vehicle of aggrandizement. Finally, in taking his focus outside Italy K. argues for the conjoined representation of Roma and Augustus in the temples erected to the pair and demonstrates how the hipmantle became common on the funerary monuments of the Greek provinces.

K. has produced a work with a clear thesis supported by much subtle argument that illuminates how divinization was a dynamic process. Those interested in ruler cult and the broad acceptance of the Principate will read it with particular benefit.