Fact-based fiction? Biographical fiction? What does one call fiction that is based on the life of a historical character? I like Joyce Carol Oates’ expression: “biographically fueled fiction.”
Here’s what she had to say about it in a review of a biographical novel about Emily Dickinson in the New York Review of Books:

In these exemplary works of biographically fueled fiction it’s as if the postmodernist impulse to rewrite and revise the past has been balanced by a more Romantic wish to reenter, renew, and revitalize the past: not to suggest an ironic distance from its inhabitants but to honor them by granting them life again, including always the stumbling hesitations, misfires, and despair of actual life….

Just a snippet … I’m packing for France: research with wine and cheese.