The final chapter traces the interaction of the protestant interest and foreign policy to the outbreak of the Seven Years War. It is a story of partial decline: within diplomatic correspondence, and more popular discussions of policy, the linkage of the protestant interest and the balance of Europe observed in earlier chapters occurs less frequently. Phrases such as the ‘common cause’ and the ‘Old System’ appear instead. The chapter explores why this shift happened. The explanation partly lies in structural alterations to the international system. International relations were becoming more complicated as the number of ‘great powers’ increased. Prior to 1713, France had been viewed as the main (but not sole) threat to European protestantism. The Grand Alliance, even with catholic members, could, therefore, function as a protestant shield. French power declined after Louis XIV's death. George I stressed protestant unity in the 1720s because one of his key diplomatic adversaries was now catholic Austria. Relations with Austria improved after 1740 so it seemed less opportune for George II to stress confessional difference. However, confessional language did not entirely disappear. Indeed the chapter illustrates how confessional language was variously deployed between 1740 and 1756, thus indicating its continuing utility and flexibility. More importantly, though, Prussia's rise to great power status during the period upset several assumptions that had dominated British and Hanoverian thinking since 1688. The changing relationship between Britain, Hanover and the leading protestant powers, Prussia and the United Provinces needs to be considered, as do Frederick the Great's policies and personality. The 1740s witnessed a very public dispute about the continuing suitability of the personal union. How closely this dispute was mirrored amongst the political elite will be discussed, as will the changing nature of the duke of Newcastle's attitudes towards Hanover. It will also be possible to consider the strategic direction of foreign policy and whether the paths of Britain and Hanover were converging or diverging.

The chapter combines analytical and chronological discussion so it is helpful to begin by providing a brief narrative sketch. Following the end of the War of the Polish succession, Austria was at war with the Ottoman empire from 1737 to 1739. Austrian participation in the war resulted from an alliance with Russia and the Russians gained far more than the Austrians from the conflict. This was symptomatic of a broader problem.