Portugal and the Development of the Law of the Sea in Western Europe

Abstract This article examines Portugal’s role in the development of the law of the sea in Western Europe between the fifteenth and seventeenth centuries. It argues that the Portuguese voyages of discovery in the fifteenth century, which led to a near century-long Portuguese monopoly of the lucrative spice trade between the East Indies and Europe, were the catalyst for that development. When the Dutch East India Company challenged Portugal’s monopoly at the beginning of the seventeenth century, it commissioned Grotius to justify its position, which he did in his most famous work, Mare Liberum . From the ensuing ‘battle of the books’ between Grotius and his critics, including the Portuguese scholar, Seraphim de Freitas, the regimes of the territorial sea and high seas were eventually forged and later codified in the 1958 Geneva Conventions on the law of the sea.