Reconquista means "reconquest" and is generally used to describe the re-population of the southwest American territories by Mexicans (since their land was originally taken by the United States).
If people knew about the cause of the bubonic plague, they would have definitely acted on it. They might have to distance themselves from various activities. People could compare the Bubonic plague and the Corona Virus because of it wide scope and it’s place of Asian origin.
As we know....the Roman Empire was very, very successful.....but if we look closely; I believe it's quite easy to distinguish by which means the Roman Empire used to grow. Rome just loved to war aka conquest other countries...it would use its resources and force them to pay tributaries (payment to the person whom conquered them). They had an incredibly good army..their military techniques were incredibly smart..and they also had war machines; which greatly contributed to their power on the battlefield. As far as I know, Rome rarely made alliances and agreements...Christianity was after the fall of Rome.
This being said to expand and grow, it's quite obvious that the Roman Empire went on conquests and war to expand and thrive. Alas, all Empires fall...as did the might Roman Empire.
Thus, your answer.