Despite all these measures, the Empire suffered several major setbacks in the course of the 6th century. The first one was the plague, which lasted from 541 to 543 and, by decimating the Empire's population, probably created a scarcity of labor and a rising of wages. The lack of manpower also led to a significant increase in the number of "barbarians" in the Byzantine armies after the early 540s. The protracted war in Italy and the wars with the Persians themselves laid a heavy burden on the Empire's resources, and Justinian was criticized for curtailing the government-run post service, which he limited to only one eastern route of military importance.