Margaret Thatcher’s time in office defined an era-a Golden Age of conservative leadership. She made the Conservative party more open and inclusive. Lady Thatcher understood that conservative principles are for everybody, not tied to special interest groups or trends. Conservative ideas must win people over first, before conservatives can win their votes later. She won arguments with humor and ironclad reasoning. She understood that honor and conviction could change minds-and crumble despotic regimes to the ground. In Margaret Thatcher on Leadership, Nile Gardiner and Stephen Thompson outline the critical lessons conservatives can learn from Lady Thatcher on articulating conservative principles to a broader audience, cutting through bureaucratic messes to achieve goals, and standing up to aggressive regimes.