Social networks as a concept was developed through social psychological work on the communication and leadership structures of small groups, and in sociological and anthropological work on kinship and community relations. From the 1960s, this idea came to be extended to a wider range of social relations (especially economic and political relations) through the formulation of mathematical models of networks. Advances in computing technology allowed the construction of more systematic and more powerful network methods.The aim of this collection is to bring together the principal sources in the development of the techniques of social network analysis, from early metaphorical statements in Simmel and Radcliffe-Brown, through the more systematic explorations in sociology and social anthropology to contemporary formalizations.A new introduction explores the history of social networks and highlights the arguments of those who treat social network analysis as a loose, qualitative approach, as well as those who see potential in its technical, mathematical uses.