Roman history tends to fascinate me. There is just this amazing idea behind it because it is something physical in our world. It is there, and it used to flourish. It lasted for so long that no one is sure how it was founded and instead we have the legend of Romulus and Remus. Anyways, let me get to the point of my question. I do not know the exact number of the population of Rome after they were invaded by the Visigoths, but I know for certain they had at least a million citizens. After Rome was Sacked what happened to them? What did the poor commoners do? Did they just go to some other city-state on the Italian Peninsula? How about the wealthy Romans that have their roots among the first families of Rome? I get that they were invaded, but does that mean suddenly all economic activity of Rome halted? The businesses were still there... did any of them continue to function? To sum up my question in a single sentence, I’m asking what did Roman citizens who were alive during its fall, and had lived in Rome all of their lives before hand, do after it fell?
Rome was actually sacked 4 times in the fifth and sixth centuries. To begin with, it is not thought Rome still housed over 1 million people in 400~CE. The Imperial court and administration had abandoned the city a century ago, taking with them those who were drawn to the city by the lure of power and empire. Many of these had gone off to follow the administration to one of the regional capitals (Trier, Lyon, Arles, Milan, Sirmium, etc.) or wound up in Constantinople after its founding. Many of the elite followed the power, but some great Italo-Roman Senatorial families did remain. In 400 CE maybe 800,000 remained in Rome, which was still fantastically wealthy and pampered by Imperial patronage as a symbol of Imperial grandeur. But between the Visigothic sack in 410, the much more brutal Vandal sack a generation later, and Theodoric the Great's attempt to revive Italo-Roman fortunes at the beginning of the 6th century, the population is thought to have dropped to between 200,000 and 300,000. Still one of the four great cities of the Empire, but nowhere near its former glories. By the end of the Gothic Wars half a century later its population was thought to have fallen to around 15,000. There are reports of farms and graveyards inside the walls, and many lived in the fortified ruins of the Colosseum for defensive purposes. The Plague of Justinian and the 30 years of brutal Romano-Gothic warfare in Italy devastated the city, and it would not recover for well over a thousand years. All but a handful of Roman elite familes abandoned the city during the war, mostly bound for Constantinople, and they never returned. The Senate is thought to have stopped meeting, in Rome, in the 540s. Of the very few Roman elite familes to remain in Rome, two would go on to become the powerful and influential medieval houses of the Coloni and Orsini, who would be prominent in Papal and Urban Roman politics for over a thousand years. But while Rome continued to be a great symbol in the Middle Ages, its days as a major metropolis would not return until the Industrial Era. At its medieval height, Rome was thought to house less than 30,000.