This article provides a case study of four late nineteenth-century share flotations of Indian railway companies. It highlights an important gap in the historiography of Indian railway finance, which has focused on the period up to 1875. The role of N. M. Rothschild as lead underwriter and its relationship with the India Office, managing agents, and investors is analysed. This gives an evolving picture of mutual dependence between the City and Whitehall in the financing of the British Empire's largest investment programme. Gentlemanly capitalists are shown to combine the self-reinforcing roles of arranger, investor, and informal government advisor.