In the wake of Anson's circumnavigation of 1740–44, and more than likely at Anson's suggestion, in 1749 the First Lord of the Admiralty, Lord Sandwich, had come up with a plan to send British ships to the Falkland Islands and then into the Pacific. From the Juan Fernandez Islands, they were to head due west, searching for islands or undiscovered land that could be used as a base from which merchants could break into the closed markets on Spanish America's Pacific coast.
Preparations for the expedition were carried out openly and when details reached Madrid, the Spanish authorities, familiar with Anson's suggestions about the matter, protested vehemently. Since the British government was conducting trade negotiations with Spain at the time, the expedition was cancelled.
Anson had died in 1762, and Sandwich had been dismissed from the Admiralty but the new First Lord, Lord Egmont, decided to launch a modified version of Anson's 1749 plan in 1764.
The main point of the exercise was to find a suitable site in the South Atlantic for a settlement where ships could refit and resupply on their way to the Pacific via Cape Horn. Egmont, in fact, described the Falklands as ‘the key to the whole Pacific Ocean’ because of their dominant position just east of the Strait of Magellan.
Since Spain claimed the Falklands but had not occupied the islands, there would be strong objectives to an overt scheme to claim them, to preparations for the expedition were a somewhat furtive affair. Only the Admiralty and George III knew the full details, and most members of the government were kept in the dark to avoid a repetition of the 1749'episode when diplomatic considerations forced the cancellation of the Falklands and South Sea venture.