This graph shows the population of Rome in historical process. It decreases significantly in 6th century because of Ostrogothic and Lombardian wars. Compared to the older figures, 19/20 of the population is no longer there after 6th century. So size of the habitated city must decrease accordingly. So my question is: What happens to the areas where the population used to live?
Do artifacts temples sculptures buildings just disappear after the wars?
Does life continue, even if a little, in those parts of the city, or is it turned into an abandoned area or a forest?
See /u/bitparity's answer here.
/u/mythoplokos's answer here and the resulting discussion covers the fate of various monuments.
u/sunagainstgold's response here discusses people's perceptions of medieval Rome and he also touches on what happened to the ruins.
/u/toldinstone discusses Rome within the wider context of how cities become "buried" over time.