Kate Sullivan, Allure magazine
Benjamin Franklin wrote, "Where there's marriage without love, there will be love without marriage." But how many affairs are love stories? We cast a wandering eye on mistresses.
756: Year Chinese emperor Xuanzong's concubine Yang Guifei was killed by his imperial guard because they blamed her family for a rebellion. The emperor mourned her terribly, and she became the subject of art and poetry.
4: Number of children Agnès Sorel had with King Charles VII of France; he acknowledged all of them. Sorel was the first officially recognized royal mistress in Europe and was known for influencing the king.
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56: Number of known mistresses kept by King Henry IV.
1: Number of mistresses Henry IV was loyal to (taking no others at the same time). She was Gabrielle d'Estrées, who wrote his diplomatic dispatches and shared his tent on the battlefield, even while pregnant.
18: Years older Diane de Poitiers was than her lover, Henry II of France.
3: Hours per day that Poitiers, a strawberry blonde, went horseback riding. She wore a black velvet mask to protect her alabaster skin from the sun. She also bathed in asses' milk and slept sitting up.
1883: Year mistresses in Japan (gonsai) lost their legal protection, which was the same that wives had.
1910: Year King Edward VII's mistress Alice Keppel was invited to his bedside as he was dying, by his wife, Princess Alexandra.
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327: Number of days Prince Edward of England served as King Edward VIII before abdicating the British throne to marry his twice-divorced American mistress, Wallis Simpson.
4: Days into her White House internship a 19-year-old Mimi Alford was when she says she lost her virginity to President John F. Kennedy.
1973: Year Prince Charles wrote to a friend about the marriage of a former girlfriend: "I suppose the feeling of emptiness will pass eventually." But he never did get over Camilla Parker Bowles-and after an affair, he married her 32 years later.
1992: Year political consultant Betsey Wright called the revelations of presidential candidate Bill Clinton's affairs "bimbo eruptions."
59: Age of Judy Lewis, the supposedly adopted daughter of actress Loretta Young, when she revealed that she was her mother's illegitimate child with the married Clark Gable.
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28: Percentage of married men who said in 2007 that they had cheated on their current partner.
2010: Year the wife and mistress of a Chilean miner met at a rescue camp while he was trapped 2,047 feet underground. Their fight had to be broken up by Red Cross workers.
15: Estimated number of women Tiger Woods had extramarital affairs with, causing a scandal in 2009 and a divorce that was finalized in 2010.
14,710,000: Approximate number of members on Ashley Madison, an online dating service for cheaters. The company slogan: "Life is short. Have an affair."