The bubonic plague of 541-543 to some extent hinders the war in the East, which drags on under other generals.
First noted in Egypt, the plague had from there passed through Syria and Asia Minor to Constantinople.
The so-called Plague of Justinian is the first known pandemic on record, and marks the first firmly recorded pattern of bubonic plague.
This outbreak is thought to have originated in Ethiopia or Egypt.
Constantinople, a huge city, imports massive amounts of grain, mostly from Egypt, to feed its citizens.
The grain ships may have been the source of contagion for the city, with massive public granaries nurturing the rat and flea population.
At its peak, the plague is killing five thousand people in Constantinople every day.
The plague kills at least two hundred and thirty thousand in Constantinople (before counting stops) and perhaps two million or more in the rest of the empire.
Emperor Justinian contracts the disease but recovers.
Based on Procopius' description of its symptoms at Constantinople in 542, the disease has appeared in its more virulent pneumonic form, wherein the bacilli settle in the lungs of the victims.
The appearance of the pneumonic form is particularly ominous because it may be transmitted directly from person to person, spreading the infection all the more readily and producing exceptionally high mortality rates.
Comparative studies, based upon statistics derived from incidence of the same disease in late-medieval Europe, suggest that between one-third and one-half the population of Constantinople may well have died, while the lesser cities of the empire and the countryside by no means remained immune.
