Clothing made to support breasts has existed since ancient times. A Roman mosaic from the 4th century depicts women wearing bandeau-style bras called strophium. An Indian play from the same period mentions its heroine wearing something strikingly similar.

“No one person invented the corset or the bra,” says Valerie Steele, Director of The Museum at the Fashion Institute of Technology. “They were developed in different places and many people took out patents over the years improving or changing their design.”

As fashion changed, undergarments changed with it. “Bras are a steward of fashion,” says Cheree Berry, author of Hoorah for the Bra. Sometimes, a flatter bosom was in style—as in Ming Dynasty China (1368-1644), when women achieved the courtly fashion of flattening their chests with a dudou, or in America and Europe in the Roaring Twenties, when bandage-inspired bras helped flappers achieve boyish-straight figures. Other times, curves were en vogue—enter the bust-enhancing bullet bra and Wonderbra of the 1950s and ‘60s.

“There was a bra product for all fashion needs… Poses for backless dresses, strapless bras for strapless dresses, Lycra for bras that allowed us to stretch, move, get fit… [bras] became fashion unto themselves,” says Berry.

Here are 14 pivotal moments in the evolution of the bra.

The corset reigned supreme for centuries, especially in Europe. During the Middle Ages, both genders wore waist-minimizing garments, though the corset as we think of it today evolved to be worn mainly by women.

By the 1500s, it took more or less the form it would take for the next 500 years: Fabric reinforced by solid strips, or ‘stays,’ made of hard materials like horn, whalebone, or wood (later replaced by metal and synthetics), laced tight.

The shape of corsets shifted as the “ideal figure” for women evolved, though an emphasis on a narrow waist that accentuated the breast and hips was the most enduring. By the turn of the 20th century, a few enterprising corset-wearers began to break free, taking fashion, and their fellow woman, with them.

The year the Eiffel Tower rose over Paris, another convention-defying structure was being formed: The first modern bra. French inventor Herminie Cadolle, fed up with uncomfortable corsets, cut one into two pieces: An upper part supporting the breasts with shoulder straps, and a second, lower part to support the waist.

She presented her invention at the World Expo of 1900 in Paris under the name “bien-être,” or “well-being,” and by 1905, was selling the upper half separately as a “soutien-gorge”—the term still in use to describe bras in French today.

American socialite Mary “Polly” Phelps Jacob’s invention was inspired by a wardrobe malfunction: When her corset poked through her dress before a ball, she and her maid replaced the stiff undergarment with something more flexible: two handkerchiefs sewn together and tied with pink ribbons. It caused a sensation in her influential social circle, and she patented her “backless brassiere” under the pseudonym “Caresse Crosby” in 1914.

“The influence of World War I really made the bra take hold,” says Lora Vogt, curator of education at the National WWI Museum and Memorial. “Women began to work in the war industry, ammunition. You can’t do that in a corset,” says Vogt.

Beyond the changing demands placed on women, corset production decreased for another practical reason: Wartime rationing. According to NPR, 28,000 tons of steel was diverted from corsets to the American war effort; enough to build two battleships.

Modeled after the scultetus binder, the simple bandeau design, consisting of a band of fabric pulled tightly over the chest, was designed to flatten the bosom in to the then-fashionable flapper style.

"Perhaps the most important development which improved bra fit was the introduction of graded cup sizes. Until that point, there was no way for manufacturers to differentiate between chest size and breast volume,” says Lorraine Topper, researcher and editor at The Underpinnnings Museum.

There is some debate on who was the first to introduce cup sizes; In 1932, Formfit introduced three cup sizes: Small, average, and full. S.H. Camp & Company used the now-ubiquitous sizes A, B, C and D as early as 1932, but Warner is often credited (and takes credit for) coming up with the alphabetical system, or at least bringing it to the mass market.

Did you know? Maternal corsets of the 1800s were the precursor to nursing bras, which were advertised to new mothers as early as the 1920s  and ‘30s.

At the 1947 British Industries Fair, nylon undergarments were advertised as “a beauty and a revolution.” Lightweight nylon replaced heavier, pricier fabrics like cottons and satins, rendering bras and corsets more comfortable—and affordable. Because nylon was “not suitable for hand-sewing,” writes Elizabeth Ewing, in Fashion in Underwear, “the vogue for hand-made silk, satin and crepe de Chine underwear…came to an end. Underwear became truly democratic.”

In 1941, Perma-Lift released the bullet bra. The cone-shaped cups were formed with concentric stitching that led to a severe point over each nipple. They reached the peak of their popularity in the 1950s, when “Sweater Girls” inspired by film stars like Jane Russell and Marilyn Monroe wore the bras under form-fitting sweaters that highlighted their figures.

In the wake of World War II, American fashion in bras began to overtake Europe for two reasons: the popularity of Hollywood films and America’s quicker recovery from the deprivations of war. In her 1953 work “Muffs and Morals," author Pearl Binder wrote: “In the hungry post-1939 world…the female breast is the obvious symbol of nourishment.”

Hungarian-American tailor Frederick Mellinger, the founder of Frederick’s of Hollywood, returned from his Army service inspired by the pin-up girl posters of his fellow soldiers. In 1947, he invented the padded bra. While using pads to enhance breast size was not a new concept, they became mass-produced in this era. There was even a pneumatic option women could inflate to their desired fullness.

While corset companies targeted young girls as future customers as early as the 1920s, the 1950s baby boom led to a surge in marketing aimed at teenagers.

Advertisements framed training bras as a rite of passage: “The understanding mother sends a growing girl to school in the only ‘growing’ bra. Whether she’s ten or a teen, a beTweenager has a psychological need for a bra. It gives her new poise in a new grade, whether she needs it (physically) or not.”

In 1958, chemist Joseph Silvers of DuPont patented Lycra, also known as Spandex. Unlike rubber or underwires, his invention could stretch up to five times its original length, shrink back to its original shape, and not lose its elasticity. Of equal importance was its durability: Lycra stood up to sweat, lotion, and laundry detergent.

“Synthetics gave women comfort, support and mobility,” says Berry. “Bras weren’t just body enhancers anymore.”

Canadian designer Louise Poirier’s Wonderbra was so complex, there were over 50 pattern pieces involved in its construction. Instead of relying simply on padding, Canadelle’s Wonderbra deliberately pushed up the breast to create more ample cleavage and the illusion of a larger cup size. The Wonderbra had a resurgence in popularity in the 1990s thanks to the controversial “Hello Boys” campaign featuring supermodel Eva Herzigová.

Did you Know? American inventor Israel Pilot first trademarked the term “Wonder-Bra” in 1935 to describe his improved brassiere, which featured a patented V-shaped strap and bias-cut cup.

Made of sheer nylon with elastic trimming, Rudi Gerneich’s 1965 “no bra” bra was designed to give the illusion that its wearer had on no bra at all while still providing minimal support. 1960s fashion favored all things natural—as long as you had the lean body type of supermodel Twiggy.

When asked why she invented the first sports bra, Lisa Z. Lindahl, author of Unleash the Girls: The Untold Story of the Invention of the Sports Bra and How It Changed the World (And Me), says: **“**I was solving my own problem. I was an amply-breasted runner. Running was uncomfortable. My straps were always falling down.

"It started out as a joke,” she says: “’Why isn’t there a jock strap for women?’’ Then, ‘No, really, why isn’t there a jock strap for women?’”

She began by writing down the things she needed a running bra to do: “The straps couldn’t slip, no chafing, it had to be breathable,” she says. Her friend and co-inventor Polly Smith made the first prototype: “We took two jock straps, cut them  in half, then sewed them back together again. I went running in that. I was the tester. One of my partners, Hinda [Miller], said ‘I’ll run in front of you backwards to see how much you bounce.’

Lindahl, Miller, and Smith never expected the Jogbra to be such a success: “I thought it would be a nice little mail order business on the side. We were profitable in our first full year in business and didn’t even know that was unusual,” Lindahl says.

“In 1972, Title IX gave equal money to girls and women’s sports," says Lindahl, "but it didn’t deal with young women who were either uncomfortable on the sports field or self-conscious. The sports bra dealt with those two barriers.”