A series of low walls...
Because the WIP takes place in the shadow of an empire that's fallen apart, I've been thinking about that quite a bit. (an aside: I may just have come up with a name for the first book, at least in the interim: Shadow of Empire).
It's not as if having a story take place among the detritus of a fallen empire is all that unusual. It's mostly that I've very rarely seen it done convincingly. Most stories that take place in such usually are in the boonies, where an area was controlled by an empire and then it withdrew. That's fine and good, and has it's place, but that's not so much what I'm thinking of. Most of the time when you see such a thing, it's either long after the empire crumbled and takes place when things have built up again, or it takes place in the immediate aftermath and you have a bunch of small kingdoms popping up like daisies all over the place.
Fine, but often not all that realistic. If it suits the story, it doesn't matter. I want to be more grounded, though -- in no small part I'm sure because much of my graduate study covered the period of collapsing empires, two of them. The collapse of the Western Roman empire, for one, and the collapse of the Merovingian Dynasty among the Franks, for another. I'll go more into that another time, but for the moment, two images pop out at me that I want to include in the WIP. Maybe not the scenes themselves, but at least the way they feel.
One is the image of an abandoned Rome (much of which was literally abandoned, after the Western Emperor moved his capital to Ravenna), where you have men eeking out a living by systematically dismantling the ruins of the Eternal City. The particular image I have is of a crew of men laboring in the ruins stripping copper/tin/whatever from a building. Stuff gets re-used. It's almost never completely abandoned. Much of the limestone casing stones for the Great Pyramid were carted away to build mosques and fortresses in Cairo in the 14th century, for instance. There's a reason why archaeological sites can usually be described as a series of low walls -- the bases of the walls are usually not worth plundering. Everything above them is... (okay, so that's a gross generalization, but it's basically the truth).
The other image I've got is of the end of both the Western Roman Empire and the Merovingian Dynasty of the Frankish Kingdom of Neustria. In both cases, the end came not with a bang, but with a whimper. With Rome, Romulus Augustulus was simply deposed by Odoacer, who made himself King of Italy. He wasn't even worth killing (and Odoacer didn't usually have any hesitation in that arena). He was so insignificant that we don't even know when he died (although he probably lived another 25 years or so after being deposed in 476). In the case of Neustria, the Merovingian king Childeric III had no power and only the title, and with the Pope's acquiescence Pippin the Short deposed him and locked him away in a monastery.
And yet it seems as if all the fantasy empires and kingdoms that you read about fall in an orgy of blood and fire... There's a reason for that, of course -- it's ever so much more dramatic. But the inherent drama is less important if it happened in the past, so...
Anyway, those aren't the only images that are pushing this story, but they're two of those that I came upon first, a number of years ago.