Comte de Grasse commanded the French fleet that defeated the British at the 1781 Battle of the Chesapeake.
The battle took place on September 5, 1781, near the mouth of Chesapeake Bay, off the Virginia Capes. De Grasse led 24 French ships of the line against a British fleet commanded by Rear Admiral Thomas Graves, which had 19 ships of the line.
The French victory prevented the British from relieving Lord Cornwallis’s army at Yorktown. By controlling access to the bay, de Grasse helped the combined American and French forces maintain the siege that ended with Cornwallis’s surrender on October 19, 1781.
The engagement is also called the Battle of the Virginia Capes, but “Battle of the Chesapeake” is the standard title of the English Wikipedia article. De Grasse’s naval success was a crucial part of the Yorktown campaign, although the Revolutionary War formally continued until the Treaty of Paris was signed in 1783.