Helen Gurley Brown, who revolutionized the woman's magazine as editor-in-chief of Cosmopolitan for over three decades, has died today at the age of 90, according to Hearst. Brown was "briefly hospitalized" at the New York-Presbyterian/Columbia University Medical Center at the time of her death.

Brown published her bestseller, Sex and the Single Girl in 1962, at the age of 40. During this decade she became a sexual revolution pioneer and an outspoken advocate of women's sexual freedom—the Awl points to a New Yorker article from 2009, where Judith Thurman wrote: "In everything that Brown has written or edited, she has promoted the message that sex is great, and that one should get as much of it as possible. (Ditto for money.) Just about everyone knows this, and has always known it, but in Brown’s youth few women would admit it, even to themselves."

In 1965 Brown became the Editor-In-Chief of Cosmopolitan, where she stayed at the helm through 1997. After that she stayed on at Hearst, with her name on the masthead as the international editor for all 59 international editions of Cosmo, and according to the Times she "was known for coming into her pink corner office nearly every day" until her death.

We'll have more on Brown's life later this week.

UPDATE: Mayor Bloomberg has released the following statement on Brown's death: “Today New York City lost a pioneer who reshaped not only the entire media industry, but the nation’s culture. She was a role model for the millions of women whose private thoughts, wonders and dreams she addressed so brilliantly in print. She was a quintessential New Yorker: never afraid to speak her mind and always full of advice. She pushed boundaries and often broke them, clearing the way for younger women to follow in her path. I was honored to be her friend and know how deeply she cared about the City she called home. We will miss her, but her impact on our culture and society will live on forever.”