It is a tricky deal being an authorized biographer. Charles Moore's big advantage over those who have previously tackled Margaret Thatcher is that he has been provided with material denied to them. Of the arrangement that he was offered by his subject, he writes: "I would have full access to herself ... and to her papers. She would assist all my requests for interviews with others, including access to members of her family." With her support, the Cabinet Office (the department of the U.K. government responsible for supporting the prime minister and his/her senior ministers), was persuaded to allow him to truffle among all the government papers of her time in power, including those documents subject to the 30-year rule, which states that the yearly Cabinet papers of a government will be released publicly 30 years after they were created.