The Bubonic Plague (a.k.a The Black Plague) caused a dramatic decline in the population of Europe in the 1300s.
population would decline
The plague, and wars.
black death (plague) and crusades
The short answer is: infighting and the plague.
In the third century, plague outbreaks, particularly the Antonine Plague and the Cyprian Plague, led to significant social and economic disruption across the Roman Empire. These epidemics caused a dramatic decline in population, which resulted in labor shortages and weakened the military and economic structures. Additionally, the widespread fear and suffering contributed to changes in religious practices, with many turning to Christianity for solace. The plagues also highlighted the vulnerabilities of the empire, ultimately contributing to its decline.
The Black Plague, or the bubonic plague, caused widespread death across Europe during the 14th century, leading to a significant decline in population. This resulted in abandoned villages and farmlands, which in turn led to a shift in land use patterns and a disruption of trade routes. The reduced population also impacted urbanization and influenced the overall demographic landscape of Europe.
The End Of War. The end of the plague. The decline of famine
The Plague
A lull in fighting between countries and by the decline of famine and the plague.
When People died of the Plague, the other people could get increased pay because there would be less people.
Their military defeat & their loss in the Peloponnesian War. Sparta burned all of the Athenian food supply and a plague also occurred in Athens which killed 1/3 of the population.