In a naval action during the Napoleonic Wars, French frigates defeat British East Indiamen in the Bay of Bengal.

The action of 18 November 1809 was the major engagement of a six-month cruise in the Indian Ocean by a French navy squadron during the Napoleonic Wars. Under Commodore Jacques Félix Emmanuel Hamelin, the squadron engaged in commerce raiding across the Bay of Bengal. Hamelin's squadron achieved local superiority, capturing several British merchant ships and destroying a factory of the East India Company (EIC). On 18 November 1809, two frigates and a brig of Hamelin's squadron encountered a convoy of three EIC East Indiamen bound for British India.

The Napoleonic Wars (1803–1815) were a global series of conflicts fought by a fluctuating array of European coalitions against the French First Republic (1803–1804) under the First Consul followed by the First French Empire (1804–1815) under the Emperor of the French, Napoleon Bonaparte. The wars originated in political forces arising from the French Revolution (1789–1799) and from the French Revolutionary Wars (1792–1802) and produced a period of French domination over Continental Europe. The wars are categorised as seven conflicts, five named after the coalitions that fought Napoleon, plus two named for their respective theatres: the War of the Third Coalition, War of the Fourth Coalition, War of the Fifth Coalition, War of the Sixth Coalition, War of the Seventh Coalition, the Peninsular War, and the French invasion of Russia.

A frigate is a type of warship. In different eras, the roles and capabilities of ships classified as frigates have varied.

East Indiamen were merchant ships that operated under charter or licence for European trading companies which traded with the East Indies between the 17th and 19th centuries. The term was commonly used to refer to vessels belonging to the British, Dutch, French, Danish, Swedish, Austrian or Portuguese East India companies.