Borders for the Roman Empire around 400AD had contracted quite a lot since their glory days so the author’s statement had some validity to it but could have been worded better.
Link to map for the time period in question:
https://upload.wikimedia.org/wikipedia/commons/0/04/The_Roman_Empire_ca_400_AD.png
“that stood on the far reaches of the Roman Empire”.
My vocabulary is pretty good, and I do not invent new definitions or contexts for a word or a sentence.
If the author meant that then “at the time” would have been appropriate. But based on the current rampant incompetence it is more likely there was indeed ignorance at play. It is the new norm...
