This chapter aims to show the role of oil concessions and arbitrations conducted on disputes arising from them for the internationalisation of contracts. The Sheikh of Abu Dhabi Arbitration between the British oil company Petroleum Development (Trucial Coast Ltd) and the Sheikh of Abu Dhabi of 1951 was one of the first of a number of arbitrations against oil-producing countries in the Middle East in the period after the Second World War and serves as a point of entry for this analysis. The argument this chapter advances is twofold. First, it aims to suggest that the construction of the international legal order over concession agreements shielded the economic sphere from sovereign assertions over production and resources and thereby maintained imperial patterns of domination in favour of Western states and their companies. Second, it argues that the driving force behind the making of this international legal order was the theory and practice of British international lawyers relying on notions of natural law, on creative argumentation and on repetition to establish the authority of the international legal order.