Following the failure of an earlier British naval blockade to prevent a fully laden treasure fleet sailing to Spain from Porto Bello in 1727, an action in which he had taken part, then-Vice Admiral Edward Vernon repeatedly claimed he could capture it with just six ships.

Vernon was a strong advocate of using small squadrons of powerfully armed warships hitting hard and moving fast rather than larger, slower-moving expeditions that were prone to heavy losses through disease.

[7] The British sailors and marines scaled the walls of the fort, struck the Spanish colours in the lower battery, and hoisted an English ensign.

[3] The British occupied the town for three weeks, destroying the fortress and other key buildings, and ending the settlement's main function as a major Spanish maritime base, before withdrawing.

[8] He had been one of the advocates of a more belligerent approach towards Britain's enemies even prior to this expedition, and after the victory, British Prime Minister Robert Walpole was under great pressure by the Opposition to launch similar raids along the Spanish coast.