June 1778

Action of 17 June 1778

Belle Poule and HMS Arethusa open Anglo-French naval hostilities

The war's opening shots were exchanged before either crown had issued an ordinary declaration of war.

17 June 1778, off Brittany

On 17 June 1778 a British fleet under Admiral Augustus Keppel encountered a small French naval force off Brittany and ordered the French vessels to submit to inspection or follow the British fleet.

The frigate Belle Poule, commanded by Jean-Isaac Chadeau de la Clocheterie, refused. HMS Arethusa pursued her, and the two exchanged fire in the first sustained Anglo-French naval combat of the war.

The French commander reported spotting roughly twenty British warships, at least fourteen of them ships of the line, before he refused; his own ship carried 26 guns firing 12-pound shot in the contemporary French account.

Both frigates left damaged

Belle Poule reached the French coast after the fight. The badly damaged Arethusa withdrew to Keppel's fleet, and other French vessels in the encounter were stopped or captured.

The action was celebrated in France and treated as the opening of overt hostilities. Belle Poule became a popular sensation.

When the war began, exactly

No single date is uncontested. France's treaties with the United States were signed on 6 February; France notified Britain in mid-March; relations then broke; the first naval fight came on 17 June; and on 10 July Louis XVI ordered French warships and privateers to attack and seize British naval and merchant vessels.

On 18 July, American commissioners in France still reported that neither nation had formally declared war, though both navies were already fighting.

A later French royal act treated 17 June as the official opening of hostilities. The rival battle fleets met off Ushant on 27 July — a separate and much larger action.

Sources

Researched 24 Aug 2026 7 sources not yet audited Date disputed

How this was checked

Researched from the web into a fact sheet and rewritten from that sheet. This article has not yet had an independent model audit. How the pipeline works →

Date disputed. Sources disagree; the research places it at 1778-06-17.

What the sources leave uncertain

There is no single uncontested declaration date. The alliance was signed February 6; France notified Britain in mid-March; diplomatic relations then broke; the first naval fight occurred June 17; and Louis XVI issued offensive orders July 10.
On July 18, American commissioners in France still reported that neither nation had formally declared war, even though both had begun hostilities at sea.
A later French royal act treated June 17 as the official opening of hostilities. Thus June 17 is the best event date for actual combat, but “the war begins” depends on whether diplomatic rupture, first shots or general offensive orders are used.