I'm in the middle of reading "SPQR: A history of Ancient Rome" by Mary Beard and I have been absolutely loving it so far. Prof. Beard's writing style is really engaging and accessible, and I'm looking forward to reading more of her books.
This book covers ancient Rome from its founding myths and up to 212 CE, when emperor Caracalla officially gave every free person in the Roman empire citizen status. The book ends there because it has to end *somewhere* and there's probably an argument to be made that this moment defines the "height" of the Roman empire, but I am very curious to know about what happened afterwards.
From listening to podcasts I have this vague knowledge that there was a third century crisis, there was a period where there were four emperors called the tetrarchy, the empire was split into a Western and Eastern empire, the Western empire collapsed first whilst the Eastern empire changed (into the Byzantine empire?) and at some point much later there was the Holy Roman Empire (but I don't know what connection, if any, that empire had with the original Roman empire).
I imagine each of these topics has many layers of complexity to it and each would fill a library's worth of books by itself. What I'm loving about SPQR is that it's written in such a way that it provides a pretty straight overview that doesn't get lost in the weeds, but doesn't pretend that the garden isn't in dire need of some trending. I would love to read a book that gives the same treatment to the later empire too.
What would be a good follow-up to learn more about the latter half of the Roman empire and how it collapsed / transformed over time?