ABSTRACT
This chapter deals with the Portuguese strategies to counteract the French and English acquisition of Portuguese maritime knowledge during the critical period of the 1550s and 1560s. The study of the correspondence of a Portuguese ambassador to France and England will be used to understand how Portugal attempted to stem the flow of Portuguese maritime knowledge and expertise from entering French and English service. The chapter focuses on the Portuguese Mare Clausum and Secret Science policies, and demonstrates the difference between these policies and their actual results.
