The obituary of an Australian veteran of WWI triggered a five book series (of which only three were published) set in an alternate reality that may have been the creation of the dying veteran's mind. It became the saga of a family of near immortal telepaths, but everything had to limited to what the veteran could imagine, or the basic premise failed.
What started out as a limitation became an inspiration as I charted my imaginary veteran's life (1898-2005) and turned him into an American dough-boy in Black Jack Pershing's 1st Army. He served in the French Foreign Legion between the wars, returned to the American Army for WWII and retired after Korea, going into business and dying in a California Veteran's Home. I even sent him to sea in the Matson Line ships for a while to broaden his horizons.
All this involved a lot of research and triggered so many ideas that I could have written a twenty book series before I used them up.
The three books published had good reviews, but poor sales so I didn't offer the fourth and fifth books and even withdrew the first three to give me the freedom to do the idea the justice it deserved.
I've now rewritten the five books into two longer books and have the problem of categorizing them for a publisher.
How do you define a speculative saga that may be the product of a dying man's mind that explores the effect of telepathy and immortality on a race, postulates an interstellar Diaspora of humanity in sub-light vessels, has five intense romances and two satisfying secondary ones, and ventures into feudal and advanced societies in equal measure?