Hey MMI,

Make up all the facts you want as long as you make it clear your story is a piece of fiction. If the inflamous Howard Hughes 'autobiography' was presented as a fictional story, then no one would have been surprised when it was not real and (maybe) the author would not have been sued or gone to jail.

If the person is dead - long dead, and relyable facts about him are not known, or are scarse, then as long as you call your work 'historical fiction', then I think you are O.K.

Or at least present your story as based on questionable information. I wrote one like this (see 'Letter from the Inquisition, written 10-08 or so).

Neal