The War of Jenkins’ Ear has been identified as the first large-scale war between European empires that had the Americas as both the cause and the scene of the conflict. The scale of the war forced the Spanish empire to develop a massive defensive plan in the Caribbean. However, in general, little attention has as yet been paid to the plan’s details. Through the study of mainly unpublished news sources, this paper aims to document, analyse and demonstrate the pivotal role of the field fortifications in the successful defensive plan of the island of Cuba against British attacks between 1739 and 1748. This will permit the redefinition of a series of identifying features of the Spanish Caribbean fortification of this period.La guerra del Asient...