Byzantium: the Surprising Life of a Medieval Empire by Judith Herrin "takes a fresh approach and focuses on manifold aspects of Byzantine culture, civilization, and religion."
"Herrin shows that far from being ossified, the Byzantines were a highly educated society whose ancient and Christian heritages combined to give them enormous strength and resilience. So technologically advanced were they that scientists are still unable to penetrate the mystery of "Greek fire," their water-borne incendiary. Moreover, the governmental and economic structures were so sound that their gold standard was maintained without debasement for nearly 900 years."
