The British gave Arnold a brigadier general's commission with an annual income of several hundred pounds, but they paid him only £6,315 plus an annual pension of £360 for his defection because his plot had failed. In December 1780, he led a force of 1,600 troops into Virginia under orders from Clinton, where he captured Richmond by surprise and then went on a rampage through Virginia, destroying supply houses, foundries, and mills. This activity brought out Virginia's militia led by Colonel Sampson Mathews, and Arnold eventually retreated to Portsmouth to be reinforced or to evacuate.