Dr David Starkey shows how Winston Churchill's biography of his ancestor John Churchill - which was also serialised in the Sunday Times - changed the way Winston was seen by the public and politicians, and so prepared the way for his return to power.

The first volume reinforced the perception of him as a man past his time, a warmonger. But the second volume, with its brilliant depiction of John Churchill's march to the Danube and stunning victory at Blenheim, began to mark out Winston as the only leading politician who truly knew war.

As further volumes appeared, and the threat from Hitler became obvious, people increasingly began to see Winston as the man of the hour.