THE PESTILENCE ARRIVED in Constantinople in 542. Within ten days the city was utterly transformed. There was a terrifying absence of moral logic to the plague. It struck down rich and poor, virtuous and wicked alike. Procopius records the death rate in the city leapt to five thousand a day, and then to ten – probably a wild guess, but it says something of the staggering scale of the epidemic. Hospitals were quickly overwhelmed. Doctors were helpless to explain the plague’s origins, let alone how to treat it.

