Two images of prime ministers fill the headlines. The first stresses how dominant they are: cabinet government has been replaced by prime ministerial government. The second speculates on when they will fall, as they so often do. How can the picture of both the all-powerful and the weak be consistent? This book seeks to explain how prime ministers work and what are the conditions that allows both conditions to prevail, depending on the skills of the prime ministers. Comparing four parliamentary systems (Australia, Canada, New Zealand, and the United Kingdom) over the past 40 years, it examines the way that prime minister win and keep power, and the means by which they choose to run their governments. It is a study in the exercise of power, in the importance of maintaining links with all parts of the political system and, above all, in the craft of being prime minister.