In 1789 the Viceroy of New Spain, Manuel Antonio Flórez, instructed Martínez to occupy Nootka Sound, on Vancouver Island in present-day British Columbia, build a settlement and fort, and to make it clear that Spain was setting up a formal establishment. The Russians were threatening to take the sound, and in May 1788 the British fur trader John Meares had used Nootka Sound as a base of operations and claimed purchase of land there from the indigenous Nuu-chah-nulth people. Martínez, then ranked "piloto primero" and "alférez de navío" (Ensign or Sub-Lieutenant), led an expedition that arrived at Nootka Sound in early 1789. The force consisted of the warship "La Princesa", commanded by Martínez, and the supply ship "San Carlos (el Filipino)", under Gonzalo López de Haro. He gave Nootka Sound the name "Puerto de San Lorenzo de Nuca". The expedition built a settlement there named "Santa Cruz de Nuca", including houses, a hospital, and the presidio Fort San Miguel.