By 1781, the sixth year of the American rebellion, British strategic focus had shifted from the northern states to concentrate in the south. Canada's governor, Frederick Haldimand, was responsible for the defence of the Crown's largest colony against the threat of Franco-American invasion, while assisting overall British strategy. He cleverly employed his sparse resources to vigorously raid the rebels' frontiers and create anxiety, disruption, and deprivation, as his Secret Service undermined their morale with invasion rumours and threatened their Union by negotiating with the independent republic of Vermont to return to the British fold. Haldimand flooded New York's Mohawk and Schoharie valleys with Indian and Loyalist raiders and, once the danger of invasion passed, he dispatched two coordinated expeditions south. One was launched onto Lake Champlain to alarm Albany and further the secret talks with Vermont. The second struck deep into enemy territory, fought a battle at Johnstown, and retreated precipitately. The rebels effectively countered both expeditions.