The British Empire was spread over six continents, seven seas and three centuries, during which its focus shifted from the Atlantic to Asia and then to Africa. At its zenith it covered more than 12 million square miles, of which Great Britain itself formed less than 1 per cent. During the nineteenth century it was expanding at an astonishing annual average of 100,000 square miles – 270 miles a day or an area the size of Hyde Park every five minutes.

The German imperialist Friedrich Naumann realised that such an empire could only be organised in a haphazard and ‘unsystematic’ way: the key to its success was ‘English elasticity … [and] adaptability … combined with an unshakeable self-confidence’. In his balanced, original and impressive new history John Darwin endorses a view