Continental Europe (and thereby Hanover) became less important to the British Empire during the Seven Years’ War. This was perhaps natural, given that the war originated in North America. It nevertheless spread to Europe, where it quickly surpassed the destructiveness of its transatlantic antecedent. France extended its imperial rivalry with Britain to Hanover, which it occupied in 1757. Hanover's vulnerability revived interest in personal union, both in Britain and the electorate. But it also prompted Britain to send an army to Hanover, seemingly substantiating imperial interpretations of their relationship. This was the policy of William Pitt the elder, whose maritime credentials have been greatly exaggerated. His association with Hanover meant that it was his resignation in 1761, and not the death of George II in 1760, that demoted the European continent in British grand strategy. Pitt's fall freed the British-born George III to pursue a more purely maritime vision of empire. But if the new king's hatred of Hanover had derived solely from the electorate's association with his grandfather, it might have ended soon after the death of the latter. George III's hostility lasted longer because of Hanover's connection with Pitt, who represented continuity with the policies and personnel of the previous reign.

Hanover resumed its former significance in British politics during the mid- 1750s, when it was once again endangered by royal policy. Prussia menaced the electorate in 1753, after British creditors protested its default on loans to indemnify East Frisian losses to British privateers. And once tensions with Prussia subsided, France threatened to extend its North American conflict with Britain to Hanover. Newcastle, by now the first minister, reverted to the language of personal union. Newcastle reassured Holdernesse, the British secretary of state accompanying George II in Hanover, that ‘any necessary support for the king's German dominions is founded on justice and declaration of parliament, and is the necessary consequence of our measures at sea and North America’.