This state of affairs, however, was complex and far from stable. The old mercantile Empire was weakened during the late eighteenth and early nineteenth centuries by a number of factors: by the abolition in 1807 of slavery in Britain itself, a movement led by the Evangelicals; by the freeing in 1833 of slaves held elsewhere in the Empire; by the adoption, after a radical change in economic perspective (due in large part to the influence of Adam Smith's The Wealth of Nations), of Free Trade, which minimized the influence of the old oligarchical and monopolistic trading corporations; and by various colonial movements for greater political and commercial independence. The Victorians, then, inherited both the remnants of the old mercantile empire and the more recently acquired commercial network in the East, neither of which they were sure they wanted, since Smith maintained that "under the present system of management Great Britain derives nothing but loss from the dominion which she assumes over her colonies."

During the Victorian Era, however, the acquisition of territory and of further trading concessions continued (promoted by strategic considerations and aided or justified by philanthropic motivations), reaching its peak when Victoria, at D'Israeli's instigation, had herself crowned Empress of India in 1876. Advocates of Disraeli's imperialist foreign policies justified them by invoking a paternalistic and racist theory (founded in part upon popular but erroneous generalizations derived from Darwin's theory of evolution) which saw Imperialism as a manifestation of what Kipling would refer to as "the white man's burden." The implication, of course, was that the Empire existed not for the benefit - economic or strategic or otherwise - of Britain itself, but in order that primitive peoples, incapable of self-government, could, with British guidance, eventually become civilized (and Christianized). The truth of this doctrine was accepted naively by some, and hypocritically by others, but it served in any case to legitimize Britain's acquisition of portions of central Africa and her domination, in concert with other European powers, of China.

At the height of the Empire, however, growing nationalist movements in various colonies presaged its dissolution. The process accelerated after World War I, although in the immediate post-war period the Empire actually increased in size as Britain became the "trustee" of former German and Turkish territories (Egypt, for example) in Africa and the Middle East. The English-speaking colonies, Canada and Australia, had already acquired dominion status in 1907, and in 1931 Britain and the self-governing dominions - Canada, Australia, New Zealand, South Africa, and the Irish Free State - agreed to form the "Commonwealth of Nations." The Dominions came to the aid of Britain during World War II, but Britain's losses to the Japanese in the Far East made it clear that it no longer possessed the resources to maintain the old order of things. The Americans were in any case ready, and indeed anxious, to replace British influence in many areas of the world.

Britain's hold on India had gradually loosened. India achieved qualified self-government in 1935 and independence in 1947. Ireland, which had at last won dominion status in 1921 after a brutal guerrilla war, chieved independence in 1949, although the northern province of Ulster remained (as it is today) a part of Great Britain. The process of decolonization in Africa and Asia accelerated during the late 1950s. Today, any affinities which remain between former portions of the Empire are primarily linguistic or cultural rather than political.