Seven Years' War: Having damaged several French vessels, British ships pursued the remainder of the fleet to Lagos, Portugal, and continued the battle there (depicted) in violation of Portuguese neutrality.

The Seven Years' War, 1756 to 1763, was a Great Power conflict fought primarily in Europe, with significant subsidiary campaigns in North America and South Asia. The warring states were Great Britain and Prussia fighting against France and Austria, the respective coalitions receiving assistance from countries including Portugal, Spain, Saxony, Sweden, and Russia. Related conflicts include the Third Silesian War, French and Indian War, Third Carnatic War, Anglo-Spanish War (1762–1763), and Spanish–Portuguese War.

Lagos is a city and municipality at the mouth of Bensafrim River and along the Atlantic Ocean, in the Barlavento region of the Algarve, in southern Portugal. The population of the municipality in 2011 was 31,049, in an area of 212.99 km². The city of Lagos proper has a population of approximately 22,000. Typically, these numbers increase during the summer months, with the influx of visiting tourists and seasonal residents. While the majority of the population lives along the coast and works in tourism and services, the inland region is sparsely inhabited, with the majority of the people working in agriculture and forestry.

The Battle of Lagos took place between a British fleet commanded by Edward Boscawen and a French fleet under Jean-François de La Clue-Sabran over two days in 1759 during the Seven Years' War. They fought south west of the Gulf of Cádiz on 18 August and to the east of the small Portuguese port of Lagos, after which the battle is named, on 19 August.