On December 20, 1780, Benedict Arnold sailed from New York with 1,500 British troops to Portsmouth, Virginia. He first raided Richmond, defeating the defending militia, from January 5–7 before falling back to Portsmouth. Admiral Destouches, who arrived in Newport, Rhode Island in July 1780 with a fleet transporting 5,500 soldiers, was encouraged by Washington and French Lieutenant General Rochambeau to move his fleet south, and launch a joint land-naval attack on Arnold's troops. The Marquis de Lafayette was sent south with 1,200 men to help with the assault. However, Destouches was reluctant to dispatch many ships, and in February sent only three. After they proved ineffective, he took a larger force of 8 ships in March 1781, and fought a tactically inconclusive battle with the British fleet of Marriot Arbuthnot at the mouth of the Chesapeake Bay. Destouches withdrew due to the damage sustained to his fleet, leaving Arbuthnot and the British fleet in control of the bay's mouth.