In the latest episode of Radio 4's new podcast on the life of Elizabeth II, James Naughtie looks at the Queen's relations with her prime ministers over the decades of her reign. Winston Churchill was in Downing Street when she came to the Throne; Tony Blair and Boris Johnson had not been born. Although she stood above the party political fray, in the intimate dealings with governments of different stripes the Queen learnt how best to deploy the Crown's influence, especially at moments of crisis. And over more than seventy years, the power relationships shifted subtly.