Even before Boris Johnson’s rollercoaster ride (2019–22), and the ensuing “blink and you missed it” premiership of Liz Truss, the high wastage-rate among Britain’s prime ministers was becoming a cause for concern. Between 1979 and 2007 Britain had just three heads of government: Margaret Thatcher (1979–90), John Major (1990–97) and Tony Blair (1997–2007). Over the next 17 years six politicians followed them in and out of Downing Street. This book, which straddles more than 30 years of prime ministerial misadventures, poses questions about the underlying factors as well as the specific circumstances for individual departures. Is the role of prime minister just becoming too difficult to perform successfully? If so, why? Has there been a decline in calibre in the candidates holding office? In exploring how the famous entrance to number 10 Downing Street has become a revolving door, the book shines a fresh light on the nature of politics and political office in the UK today.