The “Discurso del capitán Francisco Draque” (c. 1586–87), written by Juan de Castellanos, was intended to be included in the third part of his Elegías de varones ilustres de Indias. However, this section was censored around 1590. The signature in this section’s marginalia reads “Pedro Sarmiento” and it can be identified as that of Pedro Sarmiento de Gamboa, a Spanish explorer appointed by the Peruvian viceroy, Francisco de Toledo, for an expedition through the Strait of Magellan immediately after Francis Drake’s attacks in the Pacific, in 1579. This article studies the ideological implications of Sarmiento’s act of censorship. By analyzing both English and Spanish primary sources (including historiography, cartography and poetry), the present article examines the relationship between book censorship and piracy, and shows how Drake’s circumnavigation voyage impacted the way in which both Spanish and English authors claimed sovereignty and possession of territories in America. On the one hand, Sarmiento’s censorship sheds light on the contentious exchange of information between England and Spain regarding Drake’s actions in Spanish America. English writers participated in the debate about the legitimacy of the Spanish conquest of America after gathering, interpreting and translating Spanish information about those overseas territories. On the other hand, Sarmiento’s censorship reveals the Spanish monarchy’s attempt to regulate knowledge about the New World in the years that followed the 1568 Junta Magna. This particular act of suppression ultimately demonstrates that the possibility of an alliance between English protestant corsairs and Amerindian nations was a major concern among Spanish authorities.