During the early modern period, Spain's empire extended into parts of five continents, separated by vast stretches of water. Spain depended on wooden ocean-going vessels to connect and defend its imperial holdings. Timber supplies, therefore, were essential to the continued functioning of one of the largest empires in history. However, Spain had a very limited timber resource base on which various sectors of society depended. Beginning in the middle of the sixteenth century, the Spanish state set in motion a process of territorialization to control access to forest resources for naval shipbuilding, affecting state and local relations, the politics of resource accessibility, and forest management practices all over Spain. This dissertation analyzes this process over the course of two centuries, explores how the Spanish crown met the challenges of local resistance and environmental scarcity to maintain its naval power, and it ends with an analysis of the creation and implementation of Spain's first national forestry code in 1748.