Not only did Lady Mary foreshadow the future, as an early feminist, but she fulfilled the past as a "Renaissance woman" with many talents and facets: social leader, court wit, poet, commentator, fashion plate, sportswoman, politician and spy. Many scholars concede that she was "Ephelia," anonymous author of a body of provocative poetry with lesbian/bisexual overtones, that celebrates female independence in bed and out of it.

Indeed, the whole Villiers family fascinates for its sporty and sexual hues.

I first ran across Lady Mary while researching her father, George Villiers,1st Duke of Buckingham. An openly gay man who was long-time lover of sports-happy King James I, the Duke was a pioneering breeder who helped create the Thoroughbred horse. Mary's younger brother, George Villiers, 2nd Duke of Buckingham, was also a famed breeder of racehorses, and known for torrid relationships with men as well as women.

After their father the 1st Duke was assassinated in 1628, 6-year-old Mary and George and a younger brother, Francis, were adopted by King Charles I and his queen. As the rowdy Villiers children grew up, they kept the court in an uproar with their pranks. Lady Mary had a fondness for climbing trees. She went by the nicknames Mall and Butterfly. Growing up in such a sports-loving family, she probably learned to ride, shoot and fence at an early age, and remained close to her colorful brother George. Married for the first time by age 12, she was widowed by 14.

When the English Civil Wars broke out, Mary was 20. Her adoptive father Charles I was beheaded in 1649, bringing the Protestant general Oliver Cromwell to power as dictator of England. Mary's spunk and wilfulness had Cromwell so worried that she'd set a bad example for English women that he kept her under house arrest in Whitehall Palace in London during his 5-year reign. The Protestants banned sports, so Mary probably had fits of boredom in her gilded prison. Her brother Francis was killed in the fighting, while brother George and Prince Charles (later Charles II) fled to exile in Europe.

When Cromwell died in 1658 and the Protestant republic fell, Mary was released, and was reunited with George when he returned from exile -- followed by Prince Charles, who came home to restore the monarchy.

After the Restoration was launched, Mary -- like the rest of upper-class England -- went over the top into celebration of freedom and defiance of convention. Upper-class women simply did not practice sports in the masculine manner that Mary did. No different than today, the outstanding riders and fencers of the time had trainers and instructors, and worked out to hone their sporting skills -- which also had a life-and-death application in war.

With other court women, Mary shared a daring for men's clothes. In her case, however, this was a practical choice. Sweeping silk gowns made it hard to shoot, fence or ride well! High spirited and hot tempered, Mary fought duels, including one with a female rival that is documented by a court memoir of the time. Indeed, after the Restoration ended, high-profile women would not dare to wear men's clothes again in such numbers until the 20th century, when liberated spirits like Amelia Earhart and Marlene Dietrich started wearing trousers.

Though Mary married into three powerful families and had two children, she was clearly a person of non-hetero shadings. By today's standards, we don't know whether she was a "lesbian" or a "bisexual," but her period in history was so full of sexual shadings that the label hardly matters.

Like many court people of her time, the Duchess also went in for heavy drinking and was very fond of her brandy. But she didn't indulge to the same extent as her court pal John Wilmont, Earl of Rochester, who once admitted to being drunk for five years. Rochester was movingly portrayed by Johnny Depp in the recent film The Libertine.

Last but not least, Mary was beautiful, with that peaches-and-cream complexion that English women are noted for, and glossy dark-red hair, and a stately but curvaceous figure. The great court painter Anthony Van Dyck loved to have her sit for him and did several portraits of her.

In 2002, a thrill ran through the art world at the re-discovery of one of Van Dyck's long-lost portraits of Mary. It was commissioned by her foster father Charles I when she was 14 and newly widowed, and her royal foster parents were looking for a new husband for her. The painting had been missing ever since the Civil Wars, when Cromwell had the royal art collection sold to raise money for his regime.

I'm working on a full-dress piece about Lady Mary for my Outsports.com series. Today, as in her time, the Duchess has a singular story to tell.