Like the Achaemenids before them, the Sassanid rise from small-time dynasty to empire was nothing short of staggering. Beginning in the province of Fars, Ardashir I (r 224–41) led a push that saw the Sassanids replace the ailing Parthians in Persia and within 40 years become a renewed threat to the Roman Empire.

Between 241 and 272 Ardashir’s son, Shapur I, added Bactria to the empire and fought repeatedly with the Romans. In one of the most celebrated of all Persian victories, Shapur’s armies defeated the Romans at Edessa in 260 and took the Roman emperor Valerian prisoner. You can still see the cities of Bishapur and Shushtar, where Valerian was held, and bas-reliefs depicting the victory at Naqsh-e Rostam.

The Sassanids developed small industries, promoted urban development and encouraged trade across the Persian Gulf but eventually they, too, were weakened by seemingly never-ending conflict with Byzantium. Ironically it was in its last years that the empire was at its largest, when Khosrow II (590–628) recaptured parts of Egypt, Syria, Palestine and Turkey. However, after Khosrow was murdered by his son, at least six rulers, including Persia’s only two women monarchs, came and went in the following five years. Persia was in no state to resist when the Arabs attacked in 633.