Why don’t we take a break from Donald Trump and the dismaying hamster wheel of American presidential politics for one month? How about a special issue devoted to something occasionally adversarial, completely different, and yet utterly familiar? Sisters. Many of us have one, and a large proportion of the people on the planet are one. They can be the loves of our lives and the banes of our existence—often in the time it takes to boil an egg. In this issue we have enough sisters to staff a Tuscan nunnery. Deputy editor Aimée Bell, who has overseen a half-dozen or more special issues in her near quarter-century at Vanity Fair, guided the staff through this one. She comes highly qualified for the assignment: Aimée is the eldest of four sisters in a close-knit family of six children.

July 1 marks the 100th birthday of Olivia de Havilland, who will forever be remembered as Melanie Hamilton, the beatific foil to scheming, strong-willed Scarlett O’Hara in David O. Selznick’s 1939 plantation opera, Gone with the Wind. Regular V.F. contributor William Stadiem recently went to visit the actress in Paris, where she’s been living since the 1950s, far from the madding Hollywood crowd but never far from the affections of TCM shut-ins like me. De Havilland is one of only 13 people to win two best-actress Oscars. Indeed, as Stadiem points out in “De Havilland’s Bumpy Flight,” she is “the last surviving female superstar of Hollywood’s Golden Age.”

She is also, as Stadiem writes, one of the antagonists in “the most notorious family feud in the town’s history”—the other antagonist being her “unmentionable sibling,” actress Joan Fontaine. (They are the only sisters to have both won best-actress Oscars.) The ever discreet de Havilland has kept mum on the subject of her sisterly estrangement for a good 60 years. (The more voluble Fontaine, who died in 2013, was not as reticent.) I had been pestering them both for more than two decades either to explain the breakup or to just make up—with a Vanity Fair reporter in the room. Where I failed, Stadiem eventually succeeded, and de Havilland finally tells her side of the story, in pinpoint recollections that brim with sisterly love and affection—not to mention good humor. Closing in on a century, de Havilland, with her spry, elemental energy, remains astonishingly intact. God willing, she’ll pull off what she says is her next big project—living to 110.

Among the most widely known sisters of the past century were Jackie Kennedy and her younger sibling, Lee, who was often referred to as Princess Radziwill following her marriage to Stanislaw Radziwill, an émigré who emerged in London from the mists of Polish royalty. Mention Jackie and Lee to anyone alive 50 years ago and you will elicit a series of snapshots from the scrapbook of the midcentury international jet set: the sisters, in Florence as young women, visiting art historian Bernard Berenson at his villa, I Tatti; in sleeveless summer dresses, pearls, and high heels, riding a camel during the First Lady’s goodwill tour to India and Pakistan; gossiping on the deck of the Christina, the yacht belonging to Greek shipping tycoon Aristotle Onassis, whom Lee was to bed and Jackie to wed.

In “A Delicate Balance,” V.F. contributing editor Sam Kashner captures the glamour and the drama of Jackie and Lee’s relationship, including the tensions and competitiveness that sometimes frayed a close emotional bond formed during a difficult childhood with a raffish, alcoholic father, John “Black Jack” Bouvier. Lee, as beautiful and alluring as ever, divides her time between New York and Paris.

The Mitford sisters began making headlines in the 1930s and 40s largely for their forays into politics but also because there were so damned many of them. Jessica (who would become a V.F. contributor) was an ardent Communist; Unity and Diana were Fascists; Nancy was an accomplished novelist; and Deborah, known as Debo, became the 11th Duchess of Devonshire. The sixth, Pamela, stayed out of the limelight. She bred chickens. In “That Mitford Mystique,” James Wolcott looks at the enduring fascination with the formidable daughters of Britain’s Lord Redesdale. “The Mitford cult,” he writes, “not only survived the 20th century but has made a spirited go of it in the 21st with no sign of becoming winded… Individual and group biographies ... docudramas, documentaries, reminiscences, volumes of letters, and even a self-help title quench an apparently unslakable thirst for Mitford lore.” With such a wide range of personalities and convictions, there seems to be a Mitford sister for everyone, no matter how sensible or misguided you may be.

Even sisters who are the best of friends have the occasional squabble, which might result in a younger one shouting, “You are not the boss of me!” or “Who died and made you queen?” But, for the late Princess Margaret, big sister Elizabeth actually was the Queen, and very much the boss of her (as she was to tens of millions of other British subjects—let’s not even mention the Commonwealth). Despite what became a vast difference in status, the sisters shared a close friendship. In “A Most Intimate Subject,” Reinaldo Herrera reminisces about his firsthand experience of this royal relationship. During his more than three decades at Vanity Fair, Herrera has facilitated stories about subjects ranging from controversial figures of high society (the Duke and Duchess of Windsor) to business tycoons (Gianni Agnelli, Baron Heinrich Thyssen-Bornemisza); from famous political figures (Ronald and Nancy Reagan) to equally infamous ones (Imelda Marcos, Manuel Noriega). Herrera was a key wrangler for our 2003 Young Royals Portfolio, and for more than a decade he has helped produce the annual International Best-Dressed List for the magazine. Above all, he is the most congenial company you can imagine—it’s no surprise that the royal sisters liked having him around.