|Parent company||Penguin Group|
|Country of origin||United States|
|Headquarters location||New York City|
|Official website||Sentinel at Penguin.com|
Sentinel is a dedicated conservative imprint within publisher Penguin Group (USA) and was established in 2003. It publishes a wide variety of right-of-center books on subjects like politics, history, public policy, culture, religion and international relations. Its most notable books include Donald Rumsfeld’s memoir, Known and Unknown, Mike Huckabee’s Do the Right Thing, A Simple Christmas, and A Simple Government, and A Patriot’s History of the United States by Larry Schweikart.
Founder, president, and publisher Adrian Zackheim joined Penguin Group in September 2001 to launch Portfolio, the company's business book imprint. He took on the additional role of founder and publisher of Sentinel in April 2003. He has a long track record of publishing books by notable conservatives, including Margaret Thatcher, Newt Gingrich, and Bob Dole. Before coming to Penguin Group, he was the associate publisher and editor-in-chief of HarperInformation (a division of HarperCollins) and has held various editorial positions at William Morrow, Doubleday, and St. Martin's Press.