You don't have to be famous to have experienced some of the dynamics experienced by the groups in the photos above — you just have to have a sister.
Though we can only hope that others aren't experiencing sisterhood in the mold of the five identical Canadian girls known as the Dionne Quintuplets — who grew up like sideshow performers, in a home with a play space covered in glass for tourists to look through — but some of the downsides to sisterhood are practically inevitable.
For example, sibling rivalry is a common problem. Lee Radziwill has had to deal with living in the shadow of her sister, First Lady Jackie Kennedy. As Queen Elizabeth's husband Prince Philip once told Radziwill, "‘You’re just like me – you have to walk three steps behind." And a 1942 LIFE profile of Olivia de Havilland and Joan Fontaine noted that a dampening of their rivalry would lead to a dampening of their careers. The same went for columnists Ann Landers and Abby Van Buren (born Esther and Pauline Friedman). A 1958 LIFE profile of the feuding twins said that "it is the subtly ferocious personal struggle which lends their work its real fascination, and that without this goad neither of them would ever have begun it in the first place."
But, even in the face of fighting, sisterhood often prevails. Though Queen Elizabeth II and her late sister Princess Margaret had their moments of disagreement, for example, the Monarch was recently seen with a clutch that seemed to bear the image of her sister's face. And, looking back into history, it's clear that sisters can accomplish a lot when they support one another — whether they're the 19th century abolitionist and suffragist Grimké sisters, the literary Brontës, or the Hyers sisters, who worked to expand the range of roles available for African-American performers in the 19th century. And of course, like the Mitford sisters, they didn't have to go into the same field in order to make their own marks on the course of world events.
For National Sisters Day on Sunday, here's a look at some of the most famous sisters of the last few centuries.