In this chapter, we examine the almost uniquely powerful position the British prime minister is in compared to heads of government abroad, and the long list of the PM’s powers and resources. With so much in their favour, why is their performance often so underwhelming? Premierships can go by in a blur of frenzied activity. Prime ministers typically only reflect fully on the powers and resources they possessed after their period in office is over, when they are writing their memoirs, ruefully reflecting on what might have been. That doesn’t mean that there aren’t precise powers, some formal, others informal, accumulated over the years, and it is these that we consider in this chapter. The most successful prime ministers, like Thatcher or Attlee, knew, by study or osmosis, how to use them.