I did write historical... until the historians found out that the Artorius Castus they found in Sarmatia wasn't the one they were looking for :D
So, instead, I used a movie to write a historical fanfiction, choosing Tristan and Isolde as characters. You will find that the main plot is different from the real history (Saxons didn't invade from the north, for example). But the feeling should take you straight to the 5th century.
If you're open to romance, I can offer my Tristan and Isolde.
Male character is a tad rough on the edges, but protects his brothers in arms. And his woman.
https://www.webnovel.com/book/tristan-and-isolde_18696695205627305
You might be in for a cultural clash, thought, depending on where you come from. This is the end of the Roman era, with a few barbarians thrown in the mix, on a Brittonic Island.
If you ever read it, don't hesitate to comment. I love to know how readers think when they read my books.
Cheers to you, and happy reading !