In 1757, the war having spread to the continent, Cumberland was placed at the head of the Hanoverian Army of Observation, intended to defend Hanover (of which George II was Elector) from a French invasion. At the Battle of Hastenbeck, near Hamelin, on 26 July 1757, Cumberland's army was defeated by the superior forces of d'Estrées. Despite seemingly having the advantage towards the end of the battle, Cumberland's forces began to retreat. Within a short time discipline had collapsed, and Cumberland's army headed northwards in total disorder. Cumberland hoped that the Royal Navy might bring him reinforcements and supplies which would allow him to regroup and counterattack, but the British mounted an expedition to Rochefort instead, despite suggestions that it should be sent to aid Cumberland.