There are few, if any, fashion statements that have had a more lasting historical impact than Jackie Kennedy’s pillbox hat.

The First Lady arrived at the White House for John F. Kennedy’s 1961 inauguration in a wool Oleg Cassini coat and domed Halston hat, the sartorial antithesis of the other political wives in their heavy furs.

And it wasn’t just a defining moment for Jackie’s political career and style oeuvre — it was also significant for the future of Bergdorf Goodman’s Head Milliner, Roy Halston Frowick, soon to be known worldwide as just Halston.

In a new documentary from Dior and I director Frédéric Tcheng, archival footage takes us behind the designer’s bias-cut gowns and evenings at Studio 54 and into the heart of Halston’s business empire, careful not to skirt past the darker chapters that led to his brand's ultimate demise.

But first, the hat that started it all.

Not unlike generations of icons to come (Regina George and her bra-baring tank top comes to mind), it was an initial wardrobe malfunction that inspired the fashion-hungry masses.

“It was a rather windy day and she put her hand on the hat and it ended up to have a dent in it,” Halston tells a reporter in a decades-old interview. “So during all the ceremonies it had a dent in the hat, so everybody who copied it put a dent in it, which was so funny.”

Though it’s difficult to picture the former FLOTUS without the signature accessory atop her head, Mrs. Kennedy reportedly didn’t even like hats — she thought her head was too large to wear them. But, according to Vanity Fair, Halston worked overtime to make sure his pillbox was perfect. “Before the hats were sent to her, Halston would put them on his head and sit there and look at them with two mirrors, one behind him and one in front, turning his head at different angles to make sure they looked right,” Halston’s assistant, Tom Fallon, explained.

Post-pillbox, Halston went on to establish a high-fashion brand synonymous with the sexy yet laissez-faire conventions of the ‘70s, attracting the interest of the era’s icons, including Bianca Jagger and Liza Minnelli (pictured below with the designer), as well as Anjelica Huston and Elizabeth Taylor.

Halston recently premiered at the Tribeca Film Festival and will open in select theaters on May 24.