A portrait gallery at Windsor Castle, royal residence of Charles II. (Image: Public Domain)

On a wood-paneled wall in the Communications Gallery of London's Hampton Court Palace hang 10 portraits in a line. All are of women, and all the women look remarkably similar: frizzy-haired, goggle-eyed, double-chinned, and swathed in great gathered folds of silk. These are the Windsor Beauties—the 17th century equivalent of the Maxim Hot 100.

The Windsor Beauties were chosen to be immortalized because they were the most alluring and powerful women at the court of Charles II, who became king of England, Ireland, and Scotland in 1660. Being selected for a Windsor Beauty portrait meant becoming a celebrity pin-up; copies of the portraits and engraved prints of the women circulated among admirers. Baptist May, Keeper of the Privy Purse and "court pimp," in the words of Samuel Pepys, kept a stash of eight portraits in his private lodgings. Half of the women among those eight were royal mistresses.

And really, at that time, who wasn't carrying on with Charles II. The king's reign, which came after more than a decade of Puritan-fueled political upheaval, was so characterized by hedonism and licentiousness that he earned the name "the Merry Monarch."

Charles II, the party-hearty king, in a coronation portrait by John Michael Wright. (Image: Public Domain)

Attractive women were a necessary part of the king's party ethos, and he wasn't about to let a little thing called marriage get in the way of pursuing them ardently. Charles II kept multiple mistresses and fathered at least a dozen children, none of whom were born to his wife, Catherine of Braganza.

Women held unprecedented power during the Restoration era—as long as they were attractive and down for a sexual relationship with a monarch. ("Female beauty in England seems to have commenced its reign about the same time as that of Charles II," wrote George Steinman in 1871.) For women of the court, physical attractiveness was "an instrument of ambition, a conduit to pleasure and a magnet for sleaze."

Beauty meant being noticed by Charles II, which could lead to mistress status and its associated party invitations, financial security, and a free apartment conveniently located near the king's bed chamber. If a mistress gave birth to one of Charles II's children, the king was inclined to recognize the child as a noble, which boosted the social status of the woman. Charles II also bestowed duchess titles on his favored mistresses as a reward for bearing his children and being general good sports about the whole arrangement.

Even the most attractive court women, however, had to be smoothed out a little when depicted in paintings. During the 1660s, chief court artist Peter Lely painted three-quarter-length portraits of the 10 court women who would go on to be known as the Windsor Beauties. Looking at the line-up, though, it's hard to tell one from the other. Lely idealized the women's features, applying the 17th-century equivalent of photoshop to ensure they all conformed to the prevailing beauty standards. In addition to having near-identical features—and that signature I'm-sleepy-but-sexy-and-also-judging-you facial expression—the women were shown in similar poses and décolletage-baring outfits.

These two Windsor Beauties portraits, for example, do not depict the same woman:

Mary Bagot, Countess of Falmouth and Dorset. (Image: Public Domain)

Frances Brooke, Lady Whitmore. (Image: Public Domain)

The following trio of Beauties is also, despite appearances, comprised of three distinct women.

Anne Digby, Countess of Sunderland. (Image: Public Domain)

Henrietta Hyde, Countess of Rochester. (Image: Public Domain)

Elizabeth Hamilton, Countess of Gramont. (Image: Public Domain)

Public opinion of the Windsor Beauties was mixed and often mercurial. The most notorious and well-known Beauty, Barbara Villiers—variously described as a "beautiful shrew," a "lady of a thousand charms," the "all-powerful queen of love," and "the female Don Juan"—attracted a special kind of attention. Granted, Villiers, who bore at least five of Charles II's children, was unafraid of scandal and forthright about pursuing money and sex—from Charles II and others. Her "greed of gain," wrote royal biographer W.R.H. Trowbridge in 1906, "was only equaled by her man-hunger!"

Barbara Villiers, depicted by Lely as Minerva, Roman goddess of wisdom and war. (Image: