America and the rock: Chapter one

Although the Spaniards had been thrice defeated in their attempts to recover Gibraltar, they continued to view that garrison with a jealous eye, determined, if we may judge from their late conduct to seize the first eligible opportunity of wresting it, if possible, from the dominion of Great-Britain.

The war of 1762 was too unexpended on the part of Spain, and conducted with too great success by the British minister to admit of such an enterprise as the Siege of Gibraltar. The period was not however far distant, when the contest between Great-- Britain and her Colonies seemed to promise as favourable an opportunity as their warmest wishes could have anticipated particularly when, in addition to the civil war, they found hostilities taking place between Great-Britain and France. The close of the year 1777, when the news of the convention of Saratoga first arrived in Europe, was the period which they embraced to introduce themselves into this dispute. Hostilities had then been carried on for near six months between Great-Britain and France: Spain therefore judged the opportunity favourable to offer her mediation, proposing such an arrangement as she must be assured would not be agreeable to the principal belligerent powers. Great-Britain had no sooner refused her acquiescence, than the Court of Madrid espoused the part of France; and, on the 16th of June, 1779, the Spanish Ambassador, the Marquis d'Almodovar, presented to the Court of London his hostile manifesto.... The principal design of the Court of Madrid, in entering into this war, was evidently the recovery of Gibraltar.

-Captain John Drinkwater, A History of the Late Siege of Gibraltar (London, 1785)