Kitty Kelley — the best-selling author of numerous unauthorized biographies — will publish her highly anticipated bio of talk show maven Oprah Winfrey on April 13. Random House imprint Crown has ordered more than 500,000 copies for the 544-page book’s first printing. Kelley interviewed 850 sources during her three years of research.

“Oprah has spent years eliciting intimate confessionals from her subjects, but she herself has a carefully guarded persona,” says Crown executive director of publicity David Drake. “This is the first complete portrait of her — it will reveal Oprah as she has never been seen before.” When pressed to divulge details, he would only say, “It will cover all aspects of her life…It will be evenhanded. Kelley understands Oprah’s cultural importance and that is something she covers at length.” Drake went on to say that the company is not worried about any kind of backlash from Oprah herself, even though the book-loving talk-show queen remains on the air another 18 months (and there’s no telling how she’ll cover books on her new cable network, though she surely will). “I spoke to the people at Harpo this morning, and they were gracious to me,” Drake says. He pointed out that Oprah has been aware of the book for some time and that “she even said, a few years ago, something along the lines of, ‘I’m not encouraging it, I’m not discouraging it; this is America.'”

Kelley’s other biographies, best-sellers all, include The Family (about the Kennedys), Nancy Reagan: The Unauthorized Biography, and His Way (about Frank Sinatra). But somehow we suspect that this one will never be an Oprah Book Club pick.

Photo credit: Adam Larkey/ABC