Some ideas, free to use, off the top of my head.
Love the HistBuff stories. Originally i discovered RU because I wondered about the nuns of Congo.....
But history gives us many settings for possible stories.
All and every war in history, with both sides possible rapist and victims.
An unfortunate read of "Loins of Amon", a classic porn novel from Olympia press introduced me to the concept.
It might be tempting to open a history of the world, let it fall open at a random place, and set a rape story in that historical setting, that particular conflict, from Gilgamesh fucking every bride in mighty Ur, to what sad atrocity might be found in tomorrows news.
But just to mention a few, which might have the soothing distance of time:
London under the blackout of the Blitz.
The Zulu wars, and all the African colonial conflicts of the 19th and 20th century.
Vikings , Vandals , Huns and every wandering tribe from the migration period.
It is actually historically possible that a French or Burgundian maid might be gang raped by a viking, a hun and an arab if they by chance cought her in their respective raids
The pirates of the Carribean, note Defoe's note about Blackbeard's wife which I have posted elsewhere.
The Romans and almost everybody else, from Pict druidesses to Persians princeses, Batavian milkmaids to Mauritanian shepherdesses.
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