This week, our every-so-often Option This! feature pitches the story of Jessica and Diana Mitford, celebrated sisters and bitter enemies. Have at it, Hollywood—the Oscar nominations are practically in the bag.

Yours Ever,

In the last century, we ditched family for publicity. Mass media sacrificed blood ties to the cult of stardom: In its thrall, we came to need one another less and exalt the self more. Still, there are occasions when we must confront the relatives we’ve betrayed. The Mitford sisters were pioneers in navigating such awkwardness.

Writing about these antediluvian influencers means diving into a scrum. The six daughters of David Bertram Ogilvy Freeman-Mitford, 2nd Baron Redesdale, have been famous since the Jazz Age. Mitfordiana is an industry, humming with books and TV adaptations (Outrageous, the latest dramatization of the sisters’ saga, arrives next year). The last of the lot, Deborah Cavendish, Duchess of Devonshire, died in 2014 at 93, but the Mitford girls retain their knack for grabbing attention.

It helped that they were attractive, amusing, and rich (though they were loathe to talk about money). The Mitfords came of age in another polarized, celebrity-besotted era, crossing paths with Hitler, Churchill, and the Kennedys. Long before Instagram, they made for great copy.

Society columnists boosted their profile, but the sisters were the sharpest promoters of an aristocratic and larky image. Nancy, the eldest, lampooned her family in enduring novels, The Pursuit of Love and Love in a Cold Climate; Jessica justified her defiance in her memoirs, Hons and Rebels and A Fine Old Conflict. Deborah and Diana, establishment types, delivered legacy-burnishing biographies of their own. For all their differences, they shared an inborn conviction that they were worth the ink.

The Mitfords' class and romantic conflicts manage to be both antique and relevant. Modern audiences are fascinated by Downton Abbey trappings but relate to a family bitterly divided by politics. The sisters’ knack for inventing nicknames, holding grudges, and manipulating narratives is timeless.

If the sisters’ 1930s heyday keeps the BBC drama division busy, their most intriguing chapter came much later, when they were old enough to know better. That tale awaits the enterprising screenwriter. It centers on a few days in the summer of 1973 when Nancy—witty authoress and brokenhearted woman—lay wasting away from cancer.

“It’s very curious, dying,” she wrote to her friend, James Lees-Milne. “And would have many a drôle, amusing, and charming side were it not for the pain.” How very Nancy to turn a gruesome illness into cocktail banter. About heaven, the incorrigible snob had a plan: “I’ve always felt the great importance of getting into the right set at once on arrival.” But her decline, at 68, was anything but charming.

Nancy’s final days drew her sisters to her bedside. Rustic Pamela, 65, nicknamed "Woman," was happiest mucking out a chicken coop. The youngest, Deborah, 53, or "Debo," was the chatelaine of Chatsworth, one of Britain’s grandest stately homes. Between them in age were warring opposites: Jessica, 55, or "Decca," a communist who fled to America to become a celebrated muckraker, and Diana, 63, or "Honks," a glamorous but unrepentant fascist. They found each other appalling.

Still, Nancy’s illness prompted an extraordinary détente. Diana, who lived outside Paris with her ailing husband, Sir Oswald Mosley, shouldered the burden of tending to her elder sister. The stress brought on migraines and an ulcer. Jessica, living in Oakland, Calif., with her husband, civil rights lawyer Robert Treuhaft, offered to help. This forced the sisters to coöperate for the first time in 36 years.

A truce between these exceptional and difficult women could never hold. Jessica, who styled herself “the red sheep of the family,” was irreverent and combative. A heavy drinker and smoker, she loved to stir the pot. Diana, a needle in Dior, was restrained to the point of glaciality—except when it came to her far-right sympathies.

“I quite honestly don't mind what Decca says or thinks," she wrote. "She means absolutely nothing to me at all. Not because she's a Communist but simply because she's a rather boring person, really.”

Jessica condemned Diana as a vainglorious antisemite who “adored adulation [and] was completely soft on Hitler.” Diana dismissed Jessica as a showboater who twisted the past to glorify herself. “I quite honestly don't mind what Decca says or thinks," she wrote. "She means absolutely nothing to me at all. Not because she's a Communist but simply because she's a rather boring person, really.”