Reading histories of Rome's collapse mainly taught me to be skeptical of historians. At every period Rome's collapse was attributed to the <i>cause du jour</i> ignoring all the contrary evidence.
After listening to Mike Duncan's excellent "History of Rome" podcast, one of the repeated themes I noticed is that during periods when the Romans were more racist/classist/etc they had trouble. Their periods of greatest success were when they let people with the necessary skills and talent rise to the top regardless of their origin.<p>That said, they definitely had problems with failing to culturally assimilate immigrants during the late empire -- when "citizens" of the empire didn't think of themselves as Roman but instead primarily part of some other group.
The presentation of this article is really nice. I’ve only seen it on mobile. It feels like a reading experience. There was one weird thing with a paragraph’s font that was suddenly bolded. It had a link in white without text decorations, but also bolded. The green text and white link started giving me the effect of flashing.<p>Anyways, I think this site shows that even text-heavy content can be presented online in a visually pleasing way.
Rome fell because their economy depended on expansion of the empire and managing a huge empire is hard when you don't have Internet. God bless the Internet.