Four tiny triangles held together by string - that's about as small as you can get. On July 5, 1946, a striptease dancer by the name of Micheline Bernardini posed in front of cameras by a Paris swimming pool, wearing a two-piece swimsuit: the very first bikini. It was invented by French mechanical engineer, Louis Réard. Little did he know at the time, the bikini would be here to stay.

World War II was over, the Cold War had just begun. The US was testing nuclear bombs above ground in the Bikini Atoll in the South Pacific. That inspired the name for Réard's new beachwear. His ads for the two-piece bathing suit were a clever play on words: "The bikini, the first an-atomic bomb."

In reality, the French engineer didn't really invent the bikini at all. The concept of wearing scant bits of clothing goes back at least hundreds of years, to the Romans. A fourth-century mosaic at the Villa Romana del Casale on the island of Sicily shows Roman women playing sports — in ancient bikinis.

Before she started acting, Marilyn Monroe worked as a model. For her and other pinup girls, the revealing bikini was a godsend — and that's what they all wore at the time. This 1949 photograph on display at the Brooklyn Museum is titled "Marilyn on the Beach."

In the US in the 1950s, Hollywood's recipe for success included bikini-clad swimmers performing water ballet and acrobatics on water skis. Here, these two athletic mermaids are pictured cooling off. Their tops look like they're in constant danger of causing a dreaded nipple-gate moment, while their bikini bottoms appear able to withstand the top speeds behind a water ski boat.

When Ursula Andress, clad in a skimpy bikini, gracefully stepped out of the ocean in 1962, cinema-goers' chins dropped to the floor. Even James Bond (Sean Connery) had to interrupt his hunt for Dr. No to catch his breath. The same thing happened 40 years later to Pierce Brosnan as James Bond in "Die Another Day." Bond girl Halle Berry appeared in a very similar beach scene.

After featuring prominently in the Bond film franchise, bikinis started to gain even greater mainstream acceptance. Above are the latest styles being presented at the Hamburg harbor in 1963. The Capri model (left) bears a resemblance to Ursula Andress' bikini. The Sissi model (right) is meant to have a more athletic touch — and comes across as a bit more modest, at least the bottom piece.

Women were crazy about the modern bathing gear in communist East Germany, too. In 1971, a women's magazine praised the crocheted bikini — an inexpensive variation that required little material and time to produce. The only disadvantage was that the cotton yarn soaked up water and became heavy, stretching out the bikini. Today, crocheted bikinis are made with synthetic materials to dry fast.

In the 1950s, an anti-bikini organization was founded in a place known for showing lots of skin: Rio de Janeiro. The Brazilian string tanga, also known as the g-string or thong, had a rather bad reputation up until the 1970s. Nowadays, women on Brazil's beaches and elsewhere often opt for the tiniest bikini bottoms they can find.

Beach volleyball became an Olympic sport in 1996, and its popularity grew — in particular, because there is a lot for voyeuristic eyes to see. Up until 2012, women volleyball players were required to wear bikinis, until the World Volleyball Federation relaxed the sexist rule. Now they're permitted to wear anything they want — from a g-string to bicycle shorts.

The word "bikini" means literally "land of coconuts." Although the residents of the radioactive atoll have long since been evacuated from the area, the swimsuit bearing its name has lived on for decades. Four triangles and a string, which have changed women's fashion forever.