Robert Gates, United States Secretary of Defense from 2006 to 2011, has signed with Knopf to write two books; the first book will be a memoir and is tentatively scheduled for 2013, while the second book will focus on leadership and is expected to be published the following year.

Gates served as Secretary of Defense under George W. Bush, replacing Donald Rumsfeld, and continued in that capacity once President Obama took office until his official retirement last month. Prior to his role as the Secretary of Defense, Gates was in the C.I.A. for 26 years and on the National Security Council.

Gates's memoir, which is currently untitled, will offer his reflections on his role as Secretary of Defense, and will detail many of the events that occurred during his tenure there -- his review of the U.S. policy and strategy in Afghanistan, the withdrawal of troops in Iraq, his decision to replace Gen. David D. McKiernan with Gen. Stanley A. McChrystal as commander in Afghanistan, and the repeal of the military's "don't ask, don't tell" policy.

The second book will focus on Gates's philosophy about leadership, his views about great leaders he has admired, and his thoughts about effective leadership, even in the face of adversity and difficulty. Gates was named one of America's Best Leaders by U.S. News & World Report in 2008, and he was presented the Presidential Medal of Freedom, the nation's highest civilian honor, by President Obama at his retirement ceremony.