.. the nineteenth-century Empire undeniably pioneered free trade, free capital movements and, with the abolition of slavery, free labour. It invested immense sums in developing a global network of modern communications. It spread and enforced the rule of law over vast areas. Though it fought many small wars, the Empire maintained a global peace unmatched before or since. In the twentieth century too it more than justified its own existence, for the alternatives to British rule represented by the German and Japanese empires were clearly far worse. And without its Empire, it is inconceivable that Britain could have withstood them.

Empire: How Britain Made the Modern World (2003)