I was thinking. None of the main characters of any of my stories is a historical character, except Patroclus who reveals the story of Achilles in the first part of my trilogy Love Story - A Greek Tale. This story is based on historical characters, but the plot is entirely fictitious. If that story was based on the movie, you could refer to my story as a typical fan fiction slash story. This, however, was not my intention. The story is not based on the movie.
I mentioned Napoleon in two of my stories. But he wasn't a character I focused on. Those stories were just set in Napoleon's time.
My character Cagliostro from my story The Path I have Chosen is based loosely on the real person Count Alessandro di Cagliostro. But, except of the name and their interest in occultism, my character and the real Cagliostro have nothing in common. I stated that clearly in the disclaimer of said story.
Disclaimer: None of these stories and none of my other stories uploaded to GA are based on any work that was written by another author. Characters and plot of any of my stories are entirely fictitious.
According to Dusk Peterson, my stories could be termed 'original slash', as could be termed most of the stories uploaded to GA. This term, however, is not widely used. So, my stories are better termed 'homoerotic fiction' in case they focus on same-sex relationships. I uploaded a few short stories (Flash Fiction) to eFiction that do not focus on same-sex relationships. These stories are 'general fiction'.
Like Lugh stated, slash deals primarily with fan fiction. And, like Kevin said, a story involving a relationship between two males that an author creates would not be (fan fiction) slash because they are the author's original creations.
Edit to add:
I forgot my entry to the Fall Anthology. Hadrian and Antinous are historical characters. But this story is also not based on any work written by another author.
Sorry for the confusion.