The past present tense
One advantage for writers of historical fiction over historians is grammatical. They have use of the past present tense.
The broad objective of most history books is to decipher what happened in a past age from the perspective of a modern-day reader. If historians do not share or understand that perspective they alienate their readers. They must use/abuse the present to represent the past. Hence history is susceptible to reinvention not only because more records are found but also because communal attitudes and prejudices change. A new light can be shed on a past event by the intellectual and social education of an historian as much as by the discovery of a trove of documents in an attic. Let’s call that the present use of the past tense.
An author of historical fiction doesn’t have to, or probably shouldn’t, take that approach. Their skill is to write about the past as though it were the present. That’s quite a hard thing to do well because it requires the abandonment of ideas and principles entrenched in the modern day. It is also complicated by the fact that fictionalists, enlightened by history books, might know more about what was really going on than the historical characters they are portraying. The idea that you ‘had to be there’ to grasp what was really happening is preposterous. If a fictional character lived before radio and tv, let alone computers and smart phones, their knowledge base might be gossip, ballads, town criers and gutter press.
The guiding rule for writing historical fiction is to not look back, keep eyes fixed on the moment. Authors must try to stay in a present to which they don’t belong – the past is a foreign country etc.. Examples of this compelling difference between history and historical fiction can be disingenuous but here’s one from the history repeats itself stable.
Ironically, it’s the semiquincentennial of the founding of what is now the United States of America. The American colonialists threw off the British shackles because they resented being extorted by an unelected monarch, mad King George III. Two and a half centuries later, their successors are back to being ruled by a man who believes he is a king (or Jesus, the Messiah or Zeus, it’s not clear), acts like a king and is every bit as mad as George. They are not identical. Don I is native born and elected. Geo III was remarkably sane when he wasn’t having one of his fits. Otherwise, there are strong echoes.
The problem with creating a character from 1776 (as opposed to explaining 1776) is the weight of what happened next. How does a writer escape knowing that? At the time, 1776 might have felt personally momentous; it is improbable that it felt internationally momentous. Including Trump in a novel set in 2026 wouldn’t be historical fiction. It would be easy-to-write fiction, though scarcely credible when put down on paper. Almost certainly, it would differ in tone from a book written about him in 2046 or thereafter because the writer would be influenced by knowing where America, China, the Middle East and Europe went after Don I had tossed them all out of his royal playpen. To create a good novel they would have needed to write in the past present tense.
Having another tense to conjure with may be an advantage for an author of historical fiction but there’s a caveat – the past present is very tough to master.