Oprah Winfrey is the subject of a new, unauthorized biography by famed writer Kitty Kelley.

Kitty, well known for her portrayals of famous figures in her many books, from the Bush family and Nancy Reagan to Frank Sinatra and Elizabeth Taylor, spent three years researching her material.

The book promises to pull back the curtain on one of the most powerful figures on TV. The author conducted 850 interviews with numerous Oprah sources, many of whom have never before spoken to the press.

"We are excited to be publishing the first comprehensive biography of one of the most influential, powerful, and admired public figures of our time, by the most widely read biographer of our era," says Tina Constable, Vice President, Publisher, Crown Publishers.

"Anyone who is a fan of Oprah Winfrey or who has followed her extraordinary life and career will be fascinated and newly informed by the closely observed, detailed, and well-rounded portrait of her provided by Kitty Kelley's exhaustively researched book. Readers will come away with a greater appreciation of who Oprah really is beyond her public persona and a fuller understanding of her important place in American cultural history."

Oprah: A Biography is set to be released April 13, 2010.

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