The Battle of the Chesapeake, also known as the Battle of the Virginia Capes or simply the Battle of the Capes, was a crucial naval battle in the American Revolutionary War that took place near the mouth of the Chesapeake Bay on 5 September 1781. The combatants were a British fleet led by Rear Admiral Sir Thomas Graves and a French fleet led by Rear Admiral François Joseph Paul, the Comte de Grasse. The battle was strategically decisive, in that it prevented the Royal Navy from reinforcing or evacuating the besieged forces of Lieutenant General Lord Cornwallis at Yorktown, Virginia. The French were able to achieve control of the sea lanes against the British and provided the Franco-American army with siege artillery and French reinforcements. These proved decisive in the Siege of Yorktown, effectively securing independence for the Thirteen Colonies.