By the early 300s AD, ancient Rome’s population was in significant decline.

Modern historians haven’t nailed down a precise number for Rome’s population— and estimates vary— but the clear consensus is that population peaked in the first or second century AD, and then began a rapid fall.

We know the reasons why. Roman citizens were sick and tired of the corruption, inflation, taxes, crime, social decline, constant chaos, etc. and they sought greener pastures elsewhere.

Bear in mind that this was happening at a time when the barbarian invasions had already begun. Every year there were more and more border incursions from the Goths, Alemanni, etc., many of whom stayed and settled in Roman territory.

This is important to understand; even though Rome was gaining population from these migrant tribes, its overall NET population was still declining.

This means that the number of Roman citizens leaving must have been staggering.

But Emperor Diocletian decided to put a stop to all of it, and in the late autumn of 301 AD, he proclaimed his infamous Edictum De Pretiis Rerum Venalium, or Edict on Maximum Prices.

In addition to setting strict wage and price controls on EVERYTHING across the empire (in an absurd attempt to ‘fix’ inflation), Diocletian also ordered for taxes to increase... AND for everyone to be tied to the land.

No one could leave. No one could quit their job. All occupations were made hereditary, so children had to follow their parents’ profession. It was essentially the start of the feudal system.

Naturally Diocletian’s decree did not have its desired effect. Despite the emperor imposing the death penalty on anyone who did not comply, Roman citizens flouted the rules, and the population declined even more.