I am told that some people in our TikTok world believe that ancient history is irrelevant.

Those folks reckon that a fraught relationship between two vast empires – extinct for many centuries – doesn't matter much nowadays.

But I would ask them to turn on any media and consider the disturbing events boiling away in the Middle East. Whatever is presently occurring there got its start in the 7th century, just after Rome and Persia had ended a decades-long death struggle. That period is when Mohammad's elusive forces took full advantage, extinguishing one exhausted combatant and badly crippling the other.

This enormous power shift abruptly changed history's direction, toward what we have now.

Before their enervating contest, both empires regularly swatted away marauding Arab armies . . . or simply bribed their tribal leaders into alliances. If the two empires had not worn their militaries to a nub, Islam might have languished as an ephemeral Meccan cult, its prophet a mere footnote.

So how did these giant realms, which together dominated the civilized western and middle spaces of Eurasia, become so debilitated – so weakened at the same time –after centuries of vigorous co-existence, diplomacy, commercial interaction, and, yes, episodic conflict?

The Man for the Job: The fluctuating relationship of the two is a fascinating story; fortunately, noted historian Adrian Goldsworthy expertly presents it in his latest examination of the classical world's strategic dynamics. He is a fluid writer who has masterfully tackled Roman military and political history in a dozen earlier works, such as Caesar: Life of a Colossus and Caesar's Civil War: 49–44 BC.

The author has already proven himself quite skilled in utilizing the famously uneven, spotty, prejudiced (or simply absent) source material. Goldsworthy points out, however, that Iranian literature on the subject tends to be rather limited, so he admits immediately that he primarily depended on Greco-Roman accounts.

The writer deftly balances the elements of his long chronological narrativee; the Roman emperors and their actions are examined in parallel with those of their less-familiar Parthian (and later Sasanian/neo-Persian) contemporaries. This method allows a general reader easier passage through the intricate pathways and obscure personalities involved in each empire's leadership struggles.

As a seasoned popular historian, Goldsworthy ensures that sufficient supplemental support materials are included: maps are appropriate and detailed; the bibliography is extensive; and, as mentioned, the lengthy list of emperors and their king-of-king contemporaries is quite helpful, and so forth.

The Longue Durée: The author sums up the start of the long-term relationship between the empires neatly:

"The first century was a time of almost unbroken peace [Nero's war being a major exception] . . . . If the second century saw grander campaigns, with two conflicts started by the Romans and one by the Parthians, it still meant barely a decade of fighting compared to some ninety years of peace."

Goldsworthy explains that warfare became more common in the third and part of the fourth centuries, but then hostilities calmed down for an extended period.

The Romans found the armies of the Sasanian dynasty to be more challenging than those of the Parthian Arsacids. (These Sasanian neo-Persians had replaced the latter as rulers in 224 A.D.) The author believes that the military balance between the two realms "was generally fairly even," despite occasional battlefield disasters for each.

He points out that each rival developed tactical capabilities that slowly evolved to match their enemy's strengths (for example, more emphasis on cavalry, in the case of the Romans, or major improvements in Persian siegecraft). Over most of the period covered, limited war – such as large-scale raids – became a more typical "continuation of politics by other means" than winner-take-all field battles.

Goldsworthy concludes:

"While it is hard to prove that the rivalry benefited both empires and contributed to their success and longevity, it certainly does not appear to have been a major source of weakness."

Extinction of the rival empire (although occasionally contemplated), always proved, in practice, to be too expensive and unmanageable. No matter how many victories had been scored, diplomacy would become the normal default for a realistic ruler to end a war.

. . . Until. . . : Romans could no longer draw on the resources of the West by the middle 400s. For this and various other reasons, outright conflict with the Persians became "very rare indeed" as that century proceeded. After the fifth century, however, Goldsworthy notes that things between the two realms began heating up.

Suspicions grew, and negotiations started to falter during the early part of the sixth century, particularly while the Eastern emperor Justinian was busy with his reconquest of the former Roman West. Hostile actions became more frequent. In the case of the Persians, ambitious rulers clearly wanted to gain both domestic and foreign advantage while the rival was distracted. Consequently, there were several serious clashes, and even some very destructive Persian incursions during this period.

By the late sixth/early seventh, Goldsworthy emphasizes that two very extraordinary individuals arose – men who profoundly affected the empires' usual relationship.

Dropped Diplomacy: The first disruptive personality was Khusro II. Exiled as a young man, he was sheltered by emperor Maurice, who regarded him as a handy hostage with a legitimate claim to the Persian throne. Benefiting from Roman aid, this royal returned home to quash his rivals and rule all by 591 C.E..

In 602, Maur and his family were murdered by a usurper, who proved an incompetent ruler. Khusro II decided – rather ungratefully – to use this event as an excuse to "avenge" his former benefactor, and he promptly declared war.

Timing his aggression well, the Persian invader was startlingly successful, his forces driving farther into Rome's provinces than any predecessor had ever done. The Romans responses were floundering, hindered by an ongoing civil war. The author states that the victorious King of Kings now "dreamed of extinguishing the old rival once and for all."

Ignoring the lessons of the past, the implacable Khusro II refused the usual diplomatic settlements after his cascading tactical wins. The Persian convinced himself that the military triumphs would continue . . . which they did, for years.

. . . And, Out of the West: But then, another extraordinary figure arose – a brilliant warrior emperor, Heraclius. To say that this man rallied his discouraged Romans would be an understatement – he inspired them. In many ways, his accomplishments resemble – or even outstrip – the restoration achievements of third-century heroes like Aurelian.

After assuming the throne in 610 C.E., Heraclius retrained the army, enlisted the aid of a new ally (the Western Turks), and trusted that Constantinople could hold out against a massive siege by the King of Kings and his barbarian associates, while he campaigned elsewhere. Goldsworthy deftly describes the fascinating Roman counter-offensives that inserted the long war's devastations back into the Persian heartland.

Over several years, the heavy losses Heraclius and the West Turks inflicted on the enemy ultimately sparked a palace coup against the intransigent Khusro II, who was executed in 628 C.E. Finally, diplomacy was initiated; it eventually halted 25 years of savage warfare between the empires, and ended with the return of all the lost Roman territory.

Goldsworthy’s masterful 500-page narrative of this significant – but relatively unknown – massive struggle is, in my opinion, reason enough to purchase his book. (Yet another is the following chapter, which covers the subsequent rise of Islam from 632 C.E.–700 C.E. I highly recommend that you find a space on your bookshelf for the author's latest contribution to deeper understanding of the late Roman and Persian worlds.

Note: Rome and Persia is also available in e-editions.

StrategyPage reviews are published in cooperation with The New York Military Affairs Symposium

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