Two items from the author of the book itself that delve deeper into the geopolitical background of this historic period: "Roman historians claim that the Sasan

Two items from the author of the book itself that delve deeper into the geopolitical background of this historic period: "Roman historians claim that the Sasanians were aiming to recreate the first Persian empire of Cyrus the Great. This meant pushing the Iranian border with Rome further and further west. Unsurprisingly, Rome and Iran were nearly constantly at war. The two powers competed for even the smallest advantage along an ill-defined and porous frontier running south from the Caucasus into Arabia. Each war was worse than the last, and conflict spread southward as far as Ethiopia, with Iran and Rome eventually contesting control of the India trade through the Red Sea. The 6th-century Roman emperor Justinian could not break the Persian monopoly there, so he and his successors tried to dominate the overland silk trade from China. This evolved into a world war when the Turks got involved. In the 6th century the Turkish nomads of Inner Asia were the foremost military power of the age. They had overthrown the Huns who menaced Iran from the east, and had built an empire stretching from the borders of China to the Caspian Sea. With Roman backing, the Turks aimed to disrupt the Persian monopoly on the India trade by flooding Iranian markets with cheap Chinese silk which they had received as tribute from rival Chinese dynasties. Iran retaliated, and the armies of the Persian king Hormizd IV fought Roman and Turkish troops on multiple fronts and emerged victorious – further proof that the Iranian war machine was more than match for its rivals." [https://www.asor.org/wp-content/uploads/2021/02/Bonner-February-2021-ANEToday.pdf https://www.asor.org/wp-content/uploads/2021/02/Bonner-Febru...] -- Lessons from the Last Empire of Iran goes a bit deeper and concludes: I wrote The Last Empire of Iran to tell the story of the Sasanian dynasty from beginning to end. It is a narrative that covers some of the most important events of human history. And over the past 1,400 years, the story has lost none of its power. https://quillette.com/2020/07/31/lessons-from-the-last-empire-of-iran/ https://quillette.com/2020/07/31/lessons-from-the-last-empir...