Rare map of Rio Plata and the northern regions, produced during the British Invasion of the Rio de la Plata.

The invasion was an attempt by the British to open a new theatre against the Spanish and French alliance by attacking Spanish interests in South America. To this end, a force was sent to gain control of the River Plate by conquering the dominant city of Buenos Aires. On June 27, 1806, a British force of some 1,500 men under the command of Colonel William Carr Beresford occupied the city. They held control for about six weeks, before surrendering on the 14th August to a militia consisting of 550 veterans and 400 soldiers, led by Santiago de Liniers y Bremond, a French nobleman and mercenary in the service of Spain.

A second, better-resourced, invasion followed in 1807, when a force of 10,000 men under the command of Lieutenant-General John Whitelock, attacked Buenos Aires on the 1st July. The British were, however, ill-prepared for urban combat and the locals eventually overwhelmed them. The Britsh had lost substantial numbers, and General Whitelock signed an armistice with de Liniers on the 12th August and left for home. These two resounding victories, which were achieved with little help from her colonial master Spain, have led many to site them as important mile stones along the road to Argentine Independence.

Aaron Arrowsmith (1750-1823), ​”easily the foremost cartographer of his time” (R.V. Tooley), was the founder of the Arrowsmith dynasty of cartographers. Born in County Durham, he was in London by 1777 when he witnessed the will of Andrew Dury, a mapseller and publisher, and was probably training with him; he may have trained with William Faden, Geographer to the King, but was certainly employed by John Cary in 1782, as he is credited with the survey work for ​’Cary’s Actual Survey, of the Great Post Roads between London and Falmouth’, published in 1784; he is frequently credited with some of the survey work for Cary’s county atlas, ​’Cary’s New and Correct English Atlas: being a set of county maps from actual surveys’ (1787), but the sources are silent on this and by this time Arrowsmith had established his own business.

Arrowmsith’s maps set a new standard; he was assiduous in analysing and verifying his sources, discarding not only the fictional but also the uncertain, going to printed and manuscript sources for his information, and engraved in a clear and highly legible style. Arrowsmith was also diligent in revising and improving his maps to keep them current, and served as an inspiration for the next generation of (particularly American) surveyors.