The view of New York from Manhattan Island; the view of London from the heights of Hampstead; the view of Paris from the hill of Montmartre; a circle of mountain peaks; a tropical forest hiding the earth’s surface to the boundaries of the horizon. These images come to the mind when the historian takes a survey of the material for the history of the nineteenth century. This century was an age of revival as well as an age of progress; an age of discovery and at the same time an age of reflection. Knowledge was accumulated, applied, increased on a scale and over an area without precedent in earlier centuries. The centre of this intellectual activity lay in western Europe; yet the historian is compelled at every stage of his work to voyage to distant countries and take account of continents and peoples, ideas and beliefs, which had long remained on the fringes of western culture or withdrawn from the civilisation of Christendom.