Located off the southern Pacific coast of the Americas, between Chiloe and the Strait of Magellan, Madre de Dios was a small, uninhabited island with no economic relevance until two colonial episodes made it geopolitically important. These two episodes took place when Spain suspected that England had plans of establishing itself there, based on information acquired by spies in London. These suspicions were further fuelled by local rumours, old fears and indigenous information emanating from the viceroyalty of Peru. These events provide a good opportunity to study a case of the circulation of information between European and Spanish American figures, to analyse how global conflicts had a local dimension at the periphery of Spain's territory, and to learn about the history of the southernmost Chilean region.