Britain played a small role in the inconclusive but hard fought war that convulsed central Europe, while funding its ally Austria. The goal, as defined by foreign minister John Carteret was to limit the growth of French power, and protect Hanover, which was also ruled by King George II. In 1743 King George II led a 40,000-man British-Dutch-German army into the Rhine Valley. He was outmaneuvered by the French but he scored a narrow victory at the Battle of Dettingen. In the winter of 1743–44 the French planned to invade Britain in alliance with the Stuart pretender to George's throne; they were foiled by the Royal Navy. King George gave command to his son the Duke of Cumberland. He fared poorly and Britain pulled out of the war to deal with rebellion at home, where Cumberland gained fame by decisively suppressing the Jacobite Rising at the Battle of Culloden in 1746. Meanwhile, Britain did much better in North America, capturing the powerful Fortress of Louisbourg in Nova Scotia. The Treaty of Aix-la-Chapelle (1748) favoured France, which won the most victories. Britain returned the Fortress of Louisbourg to France and the French left the Austrian Netherlands (modern Belgium). Prussia and Savoy were the main winners, and Britain's ally Austria was a loser. The treaty left the main issues of control over territories in America and India unresolved, and was little more than an armed truce, and a prelude to the more important Seven Years' War.