Pakistan's Abdus Salam was the first professor of theoretical physics at Imperial College, London, and the director of the International Centre for Theoretical Physics at Trieste for almost 30 years. This paper looks at the conditions that allowed Salam to emigrate and develop a successful career in Europe as both a scientist and a scientific diplomat. The combination of colonial networks and academic policies in British India, on the one hand, and the post-colonial intellectual milieu in certain British scientific circles after 1948, on the other, provided Salam with an opportunity that would have been virtually unthinkable for the previous generation of Indian scientists. As a Pakistani theoretical physicist in Britain, Salam became one of the most authoritative and influential advocates of science for third world development. Yet, in post-colonial Britain, being from a former colony also put certain limits on Salam's aspirations. Salam's diplomatic and political career as a United Nations officer resulted from his conviction that supranational institutions represented the only chance to overcome the kind of discrimination that marginalised third world scientists in the post-imperial era.
