Changes

It is possible that the Plague of Justinian caused about a quarter of the population of the eastern Mediterranean to die or be severely affected by the plague. The Byzantine Empire, when the plague occurred, was a rising empire spreading its power through southern Europe and the western Mediterranean. It is possible the empire could have reunited the Roman Empire but the plague ultimately made this dream impossible. While we cannot be sure what would have happened if the plague did not occur, the emergence of northern Europe out of its Dark Age could have been sooner. However, another possibility is that northern Europe, as it became isolated, developed its own political institutions and relationships, leading to the rise of monarchies in northern Europe that affected the regions there different from southern Europe and Mediterranean. This may have led northern Europe to develop a very independent political history that may have not been possible without the plague. It is also possible that conquering Arab armies of the 7th century would have found it harder to defeat both the Sasanian and Byzantine Empires in the 7th century.