George Anson's voyage around the world

While Great Britain was at war with Spain in 1740, Commodore George Anson led a squadron of eight ships on a mission to disrupt or capture Spain's Pacific possessions. Returning to Britain in 1744 by way of China and thus completing a circumnavigation, the voyage was notable for the capture of an Acapulco galleon but also horrific losses to disease with only 188 men of the original 1,854 surviving.

In 1739, the riches that Spain derived from the New World were well known throughout Europe. Huge quantities of silver were shipped from Peru, carried over the isthmus at Panama and then loaded on another ship at Portobelo bound for Spain. Other ships carried luxury goods from Manila to Acapulco from where they were taken to Vera Cruz and loaded along with Mexican silver. Spain's Caribbean possessions provided sugar, tobacco, dyes and spices.

Britain had negotiated a treaty (the Asiento) that allowed the South Sea Company to send one trading vessel per year to Spanish territory plus supply slaves but private British vessels, many operating out of Jamaica, carried illegal cargoes which the Spanish attempted to intercept. After numerous incidents and with old rivalry, tensions increased leading to the War of Jenkins' Ear.

Various schemes were proposed to attack Spanish possessions. Edward Vernon captured Portobelo in November 1739 with just six ships, and a second squadron to be led by George Anson, was to sail around Cape Horn with six warships carrying 500 troops with instructions that might be described as ambitious. These were to capture Callao in Peru (the port that served the nearby capital Lima) and if possible take Lima as well, capture Panama with its treasure, seize the galleon from Acapulco and lead a revolt of the Peruvians to Spanish colonial power. An earlier proposal to also capture Manila was dropped.

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Wikipedia