Plague is older than the Black Death
When people think of plague in the Middle Ages, they usually think of 1347 to 1351. But plague appeared in Europe and the Mediterranean world more than once, over a span of centuries. Seeing the whole sequence helps put the Black Death in context, and recent scientific work has changed how historians think about it.
Researchers commonly speak of three plague pandemics. The first began in the sixth century, the second began with the Black Death in the fourteenth, and the third began in the nineteenth century in Asia. The first two fall within or near the medieval period.
The Justinian plague
The first pandemic is named after the Byzantine emperor Justinian I, who ruled in the sixth century. The best-known account of its arrival comes from the historian Procopius, who described the epidemic reaching Constantinople in the early 540s. The emperor himself is reported to have fallen ill and recovered. The disease had been traveling by sea from Egypt, and the great grain shipments that supplied the capital are often suggested as a channel.
Procopius, other writers and the surviving evidence indicate that the toll was severe, but how severe is debated. Some historians have proposed very large losses in the Byzantine Empire; others argue that the impact was more limited than the dramatic sources suggest and that the sources exaggerate. Analysis of ancient DNA from early medieval graves in parts of Europe has found evidence of Yersinia pestis, which shows the plague really reached western regions, though that evidence is still limited and open to interpretation.
The first pandemic did not end in one outbreak. Waves of plague returned in the Mediterranean world and beyond over the next two centuries, with the last recorded outbreaks usually placed in the middle of the eighth century. Then plague seems to have disappeared from the written record of Europe and the Mediterranean for several hundred years. Whether this reflects a real absence, or a loss of sources, is not entirely settled.
Effects of the early plague
Historians have debated whether the Justinian plague contributed to weakening the empire at a time when it was fighting wars and facing pressures from neighbors. Some see significant demographic and fiscal damage, with fewer taxpayers and soldiers. Others caution against giving the plague too much weight when so many other factors were operating. Similar debate surrounds the early medieval West, which was also changing as the Roman successor kingdoms formed. As with the Black Death, interpretation depends on how much weight one gives to scattered evidence.
A long gap and a new arrival
For roughly six centuries after the first pandemic faded, there is little sign of major plague in Europe. When it returned in the 1340s, many contemporaries had no recent memory of it and compared it to biblical plagues or to classical accounts. Genetic research suggests the strain responsible for the Black Death descended from ancestors that circulated in Central Asia, and the Mongol Empire’s wide-ranging connections and the stability of the Pax Mongolica are sometimes cited as part of the conditions for the disease’s movement, although this is speculation to some degree.
The Black Death and its sequels
The Black Death of 1347 to 1351 is the high point of the second pandemic, but it is better seen as the start of a long period of recurrent disease. Outbreaks followed in the 1360s, and a particularly notable one in 1361 to 1362 is sometimes called the “children’s plague” because it is said to have struck the young, who had not been exposed to the first wave, more heavily. Further waves appeared in the 1370s and in later decades, hitting different regions at different times. The pattern was local rather than continent-wide: a city might have an epidemic every decade or so, while another stayed clear for years.
Over time, towns developed more regular countermeasures, such as health boards, restrictions on travel and the isolation of the sick, as discussed in the article on plague remedies. Plague also entered the language of art, religion and everyday life, appearing in sermons, in processions and in images of death.
After the Middle Ages
The second pandemic continued well beyond the medieval period. Outbreaks occurred across Europe in the early modern era, with the last major epidemics in western Europe in the early eighteenth century, such as the outbreak at Marseille in 1720. After that, plague withdrew from Europe, for reasons that are still discussed and may include changes in trade, housing, quarantine and ecology.
The third pandemic, starting in the late nineteenth century, is when the bacterium was identified by scientists and the role of fleas and rodents was established. That later knowledge is what allows us to look back and read medieval accounts in a new light, while remembering that people at the time had no such understanding.
Why the long view matters
Looking at the whole sequence shows that plague was not a single event but a recurrent threat, and that its impact varied with the circumstances in which it struck. The Black Death was extraordinary in scale, but it was embedded in a longer history that begins in late antiquity and runs through the medieval and early modern worlds.