Goldsworthy's latest volume is an ambitious project. Having published a biography on Julius Caesar, a volume concerning the idea of pax or peace in the Roman Empire, and a volume dealing with the collapse of the Empire, his latest offering on the relationship between the Roman and Persian Empires is perhaps the most daunting of all. Goldsworthy uses his introduction to set out the reasons for this volume, stating that he wishes to examine ‘seven centuries of imperial competition as well as peaceful co-existence’ (p.2) between the two rivals. As neither could readily overcome the other, Goldsworthy's study is not just a volume which looks at military rivalry, as he notes within his own pages, ‘there is a great deal of war in the pages that follow’. But ultimately, I believe this could be described as a volume which shows the reader the ebbs and flows of international relations; war was a last resort and rarely ever decisive between the two powers. The volume ultimately draws to a close with the Arab conquests of the regions of Syria and Egypt and the collapse of the Sassanid Empire.

As ever, the key to such work is not only to point out the differences between the two foes, but also their similarities. Here, Goldsworthy chooses to focus on the longevity of both Rome and Persia. As such, each chapter is divided into sections which predominantly (due to the relative paucity of evidence from the Persian side of things) focus on the interaction with well-known Roman figures. There are Persian interactions with famous military figures such as Lucius Cornelius Sulla, Gnaeus Pompey and Marcus Crassus (amongst others). One of Goldsworthy's most evident talents is the ability to look at the Roman system and its ability to deal with its neighbours, both friend and foe; on occasion, with violence, but often, with little more than the mere suggestion of it. Goldsworthy exemplifies this with what could be considered the gold standard for Roman diplomatic showmanship. Recounting the tale of Gaius Popilius Laenus (p.38) who, in negotiations with the Seleucid ruler Antiochus IV in Alexandria, asks that Antiochus and his army leave Egypt. To gain an answer from the great military ruler, Popilius draws a circle around the King and demands that he give the consul his answer before he steps out of the diplomatic prison in which he finds himself.

That is not to say that Goldsworthy does not zoom in on some of those key conflicts and battles. This, as those who are familiar with Goldsworthy's earlier volumes will expect, is where he repeatedly finds the mark – the analysis of major battles and dramatic events in clear, crisp detail. For example, (on pp. 83–97) the battle of Carrhae is covered in great detail, and such military terms as the ‘composite’ bow and its devastating impact are explained, not only to help the non-specialist understand why these things are important, but also to create a vivid picture of the rain of arrows which Crassus infantry endured. Defeats are given more time in the volume because there are few of them. Crassus’ death and the pouring of molten gold into his corpse is recounted as is the much later capture of the Roman Emperor Valerian on the battlefield in AD 260. The gruesome details of Valerian's death are disputed by scholars, yet Goldsworthy does not spend time considering these aspects and, instead, uses Valerian's capture to focus on the structural issues within the Empire which led to defeats and reverses at the hands of enemies both internal and external. One example is that of provincial legates who possessed too many troops or successful military figures who declared themselves or their family members as emperor.

Not only does this volume consider the intricacies of the relationship between the two empires effectively, but it also provides readers with a range of excellent maps provided to give the reader a sense of geographical place. Not only do these help the reader gain a sense of geographical locations, but the maps for different phases of the conflict help the reader gauge a sense of the changing boundaries of both empires (particularly on the Roman side) with maps highlighting the change in provinces under the Tetrarchy, a notable occurrence. In addition, there are also maps which track the progress of major campaigns, such as those of Shapur I (p. 250) and the wars of Khusro II (pp. 410–411). I believe this offers this volume a unique advantage: many readers find maps extremely helpful for reference, particularly when using the antique names of countries and regions. Here, the maps themselves are almost as interesting as the story Goldsworthy is telling. The front of the volume also provides a detailed chronology of both empires accompanied by a list of King and Emperors of the houses of Arsaces and Sasan on the one side and the reigns of the Roman Emperors on the other. This allows the reader to refer back to the chronology while reading and makes the range of individuals far easier to navigate.

Goldsworthy concludes that the conflict between these two great empires had ended, in part at least, because of exhaustion. The wars of Khusro II led to the occupation of great swathes of Byzantine territory; yet the counterattack which followed and Khusro's subsequent deposal and murder left both empires severely weakened by their losses. As the Arab conquest swept the Sassanid Empire away and damaged the Eastern Empire beyond recognition, an enduring and complex rivalry ended. In the end, two reasonably matched foes were overcome by a younger, stronger rival.

This is a fine addition to the literature of the rivalry between the two and would be of great interest to both students studying either Rome or Persia and members of the public with an interest in antiquity.