Everyone who steps through the door of 10 Downing Street for the first time as Prime Minister must to some extent feel as Churchill did on 10 May 1940 when he 'felt as if I were walking with destiny.'
But what exactly is the position of Prime Minister? Where did it originate from and how has it changed in the centuries since Walpole first held the position?

Peter Hennessy is Attlee Professor of Contemporary British History at Queen Mary, University of London, and was recently elected a Fellow of the British Academy. Before joining the Department in 1992, he was a journalist for twenty years with spells on The Times as a leader writer and Whitehall Correspondent, The Financial Times as its Lobby Correspondent at Westminster and The Economist. He was a regular presenter of the BBC Radio 4 Analysis programme from 1987 to 1992. In 1986 he was a co-founder of the Institute of Contemporary British History. Professor Hennessey was Gresham Professor of Rhetoric between 1994 and 1997.