In February 1756, Amherst was appointed commissar to the Hessian forces that had been assembled to defend Hanover as part of the Army of Observation: as it appeared likely a French invasion attempt against Britain itself was imminent, Amherst was ordered in April to arrange the transportation of thousands of the Germans to southern England to bolster Britain's defences. He was made colonel of the 15th Regiment of Foot on 12 June 1756. By 1757 as the immediate danger to Britain had passed the troops were moved back to Hanover to join a growing army under the Duke of Cumberland and Amherst fought with the Hessians under Cumberland's command at the Battle of Hastenbeck in July 1757: the Allied defeat there forced the army into a steady retreat northwards to Stade on the North Sea coast.