The 9 most iconic female duos in history

Two of the founding members of the women's rights movement, Susan B. Anthony and Elizabeth Cady Stanton spent their friendship campaigning for women's suffrage, with Anthony as the vocal head of the cause and Stanton as her speechwriter.

After being introduced in 1851 by Amelia Bloomer, who popularized pants for women, Stanton and Anthony quickly became the start of a powerful wave that would bring on the 19th Amendment to the Constitution.

"No power in heaven, hell or earth can separate us, for our hearts are eternally wedded together," Stanton once wrote to Anthony.

They were firm friends until Stanton died, some 50 years after they'd first met.

Elizabeth Keckley's incredible life story includes her buying her way out of slavery before establishing a high-profile dressmaking business in Washington, D.C., where first lady Mary Todd Lincoln hired her in 1861.

The two bonded beyond a client-designer relationship to become each other's close confidantes during Lincoln's time in the White House, which was plagued by negative reports on her suspected mental illness and extravagant spending.

But their friendship hit the rocks in 1868 when Keckley published her tell-all autobiography, "Behind the Scenes: Or, Thirty Years a Slave and Four Years in the White House."

After an illness left Helen Keller blind and deaf at 19 months old in 1881, she led a difficult and lonely childhood before she met 20-year-old Anne Sullivan on March 3, 1887.

"That date," Helen later said, "was my soul's birthday."

Sullivan, who suffered from slight visual impairment, bonded with Keller as she quickly picked up nearly 600 words, multiplication, and reading Braille.

Keller became the first deaf-blind person to graduate from college, one of the first milestones in their decades-long companionship, in which Keller and Sullivan led the charge in advocacy for people with disabilities.

English writer Virginia Woolf's friendship with New Zealand author Katherine Mansfield was famously plagued with just as much affection as jealousy.

After creating The Hogarth Press with her husband in 1917, Woolf published Mansfield's writing in 1918 as one of the imprint's first works.

Their friendship suffered as they lost contact in 1919 when Woolf moved to the Italian Riviera and came across a negative review Manfield had published about her second novel, "Night and Day", in which she said it made her "feel old and chill."

Despite years of ups-and-downs amid their professional competition, Woolf wrote in her diary after her friend's sudden death that Mansfield's was the "only writing I have ever been jealous of."

The long-lasting friendship between former first lady Eleanor Roosevelt and Pauli Murray, a black and queer writer and activist, began with a protest.

Murray wrote President Franklin Delano Roosevelt a letter in 1938 to chastise him for speaking at the all-white University of North Carolina after he had touted a platform of social progress. She sent a copy of the letter to the first lady, who was notably more active with African American interest groups than her husband and intrigued by Murray's forcefulness.

The two had a common passion for debate and civic causes that was present throughout the hundreds of letters they sent over the course of their nearly 25-year friendship.

Roosevelt notably wrote about her "firebrand" of a friend in the February 1953 issue of Ebony, years before the Civil Rights Movement would reach a fever pitch in America.

While Jacqueline Kennedy has gone down in history as one of America's most stylish first ladies, her sister Lee Radziwill left an equally glamorous legacy.

Raised on Manhattan's Park Avenue before moving to an upscale Washington, D.C. suburb, Jacqueline and Caroline Lee Bouvier were born into what appeared to be a charmed life but was plagued early on by their father's womanizing, drinking, and pressure on the young sisters to succeed.

The girls became stylish and well-traveled, studying and working in Europe while maintaining high status within East Coast social circles through the 1940s and 1950s. They both married multiple men of power, with Jackie eventually becoming first lady and Lee becoming a princess.

After bonding through travel and tragedy in their adult lives, the sisters kept up glamorous appearances until Jackie's death in 1994 and Lee's in February 2019.

Actress Marlo Thomas wrote that when she met Gloria Steinem in 1967, the two were supposed to be consulting on Thomas possibly playing the emerging feminist icon in a movie.

But the two bonded over their shock when the agent who introduced them said: "I don't know which one of you I'd like to f--k first."

After hitting it off, the two became close friends and Steinem brought Thomas into the center of the feminist movement in the 1970s to champion causes that the two are still active in today.

As two of the most closely watched royals these days, Meghan Markle, the Duchess of Sussex, and Kate Middleton, the Duchess of Cambridge, are at the forefront of a more modern era for the British crown.

The Duchess of Cambridge has broken a number of royal traditions since her 2011 marriage, including taking her children's portraits herself and being poised to be the only queen of England to have a college degree.

Middleton has also reportedly been a wealth of knowledge and support for her sister-in-law, who is ushering in some firsts as she prepares to give birth to her first child months after she became the first biracial member of the royal family.