How did invasions and epidemics contribute to Marseille’s decline after Roman times?

Following the Roman period, Marseille experienced a significant decline that eventually brought the city to the brink of extinction. While the city had previously flourished as a center of Greek learning and trade, it suffered through centuries of persistent invasions and epidemics. These combined pressures devastated the urban landscape, leaving the once-prosperous port as little more than a collection of nearly abandoned ruins.12

The city remained in this diminished state until the 10th century, when it began to be repopulated under the protection of the viscounts of Provence. This revival allowed Marseille to eventually regain its status as a vital shipping and staging point for the Crusades.1