That particular illustration is an artistic interpretation of another older illustration. I wish I could place a link for reference right now but I’m using my phone and that’s no fun.
There’s a YouTube video somewhere that explains all of this and shows a more accurate physical model (or as accurate as can be reasonably expected) that is located somewhere in Bologna, which suggests that there were quite a few towers but not that many and not that tall as shown here. In any case it still had an impressive skyline for its day.
If I remember to do so, I’ll come back here and post a link.
There’s a YouTube video somewhere that explains all of this and shows a more accurate physical model (or as accurate as can be reasonably expected) that is located somewhere in Bologna, which suggests that there were quite a few towers but not that many and not that tall as shown here. In any case it still had an impressive skyline for its day.
If I remember to do so, I’ll come back here and post a link.