I had an interesting thought yesterday. I was pondering, what if some of the archaic literature we relied upon to document past events was actually fictional accounts intended to be read for leisure?

This prompted me to ask what ancient or medieval (preferably before the 15th century) do you know of? Some may describe The Iliad as historical fiction, what do you think.

P.S. Regarding fictional accounts mistook as historical, I found this enlightening discussion on reddit, libreddit link.