A historical romance.
Of, concerning, or in accordance with recorded history, (particularly) as opposed to legends, myths, and fictions.
July 4, 1776, is a historic date. A great deal of historical research has been done on the events leading up to that day.
Of, concerning, or in accordance with the past generally.
Of, concerning, or in accordance with the scholarly discipline of history.
The Royal Historical Society
Forming compound adjectives with the meaning "historical/~" or "historically":
historical-political