This was believed to be Davis Land, west of Peru, sighted by English buccaneer Edward Davis in the Bachelor's Delight in 1687, and mentioned in the writings of fellow buccaneer William Dampier.
To find it, Wallis was directed to sail westwards from the Horn for around one hundred degrees of longitude, as nearly as possible in the latitude of that cape. After he located the continent, if its coast took him too far northwards, he was to return via the East Indies. Otherwise, he should return by way of Cape Horn and the Falklands.
He should cultivate friendships with any peoples not previously visited by Europeans whom he should discover, and, with their permission, to ‘take Possession of convenient Situations in the Country’. If the newly discovered land was uninhabited, he should take possession of it ‘for His Majesty, by setting up proper Marks and Inscriptions as first Discoverers and Possessors.’ If ‘contrary to Expectation’, the quest was unsuccessful, he was to proceed across the Pacific to China or the East Indies, seeking out islands on the way.
The Dolphin sailed from the Nore on 21 August 1766, accompanied by the 30-year-old sloop HMS Swallow under Philip Carteret, who had sailed with Byron and had some idea of what the expedition was in for and thought the Swallow would be unlikely to reach the Falklands. When he sought a refit and better equipment, he was refused; when he asked for stores, he was told they had been provided and were aboard the Dolphin and the storeship that would accompany the two vessels. That was to become a sore point.