What was the first work of fiction that was generally understood to be completely imaginary (i.e. not just a fictionalized version of history or legend that people believed in?)

by LibraryLass
Searocksandtrees

hi! I'd suggest this question might do better in /r/AskLiteraryStudies or /r/AskAnthropology, but answers could well come in here; meanwhile you may be interested in a couple of earlier posts