This dissertation examines British policy in Afghanistan between 1864 and 1879, with particular emphasis on Sir John Lawrence's term as governor-general and viceroy of India (1864-69). Having achieved national renown for his exploits in the Punjab during the Indian Mutiny, as governor-general Sir John (later first Baron) Lawrence became synonymous with a particular line of foreign policy in Afghanistan, commonly referred to by contemporaries as 'masterly inactivity'. His tenure at Calcutta coincided with a critical period in Anglo-Afghan relations, on account of a protracted civil war in Afghanistan and the renewal of Russian military advances in central Asia. This dissertation explains why government ministers granted Lawrence so much latitude for formulating British policy and what motivated his 'masterly inactivity', an alluring although misleading expression. A central concern is the extent to which public criticism in Britain influenced Lawrence's decisions in India. Some of the constraints on policy-makers are also explored, including contemporary perceptions about the importance of 'prestige' to the control of India. In addition, the thesis considers some of the domestic effects of British imperialism, by reference to Lawrence's public criticism of government policy before the second Afghan war, and by analysing metropolitan reaction to the murder of the British envoy at Kabul in 1879. His utility to parliamentary Liberals and prominence in public discussion about Afghanistan in 1878 demonstrate that-after nearly a lifetime on the imperial 'periphery'-Lawrence ultimately exerted a considerable influence on politics in the imperial metropolis. A portrait of Sir John Lawrence (by George Frederic Watts; oil on panel, 1862) is currently displayed at the National Portrait Gallery, London (NPG 1005).