The French don’t remember much about 19th century President Félix Faure, according to historian Sarah Horowitz. But they do remember how he died. He breathed his last during a winter tryst in 1899 with a woman named Marguerite-Jeanne Steinheil, who’d later be known as the Red Widow.

Despite her nickname, the woman who went by “Meg” probably didn’t intend to kill her lover. However, Horowitz writes in her new nonfiction book, “The Red Widow: The Scandal That Shook Paris and the Woman Behind it All” (Sourcebooks, $26.99), “This is a book about a woman who lied her entire life.”

So, who really knows what happened?

And who really knows if, a little after the president’s demise, she was the one who killed her husband and mother? Someone did one night while Meg was very loosely tied to her bed.

Oddly, each of her toes was individually tied to the bedpost. So Horowitz can’t definitively say who committed the murders, but after spending years combing through primary source materials and getting to know Meg, she has her opinions.

“I don’t actually think she murdered her husband and mother. I think she knows who did it,” Horowitz says by phone from Virginia, where she’s a history professor at Washington and Lee University.

Meg was a middle-class woman whose era severely limited her options, yet she managed to outsmart her station in life. Despite her marriage to an untalented, struggling artist she felt no love for, Meg hatched a plan to access Paris’ social stratosphere and triumphed.

She reached those upper limits through a form of sex work that sidestepped being a prostitute or a courtesan. Meg was, after all, a married woman with ambition and handled her affairs with extreme care.