in formulating British military and diplomatic strategy. He shared with Newcastle a belief that Britain should continue to fight until it could receive generous peace terms, in contrast to some such as Henry Pelham who favoured an immediate peace. Pitt was personally saddened when his friend and brother-in-law Thomas Grenville was killed at the naval First Battle of Cape Finisterre in 1747. However, this victory helped secure British supremacy of the sea which gave the British a stronger negotiating position when it came to the peace talks that ended the war. At the Treaty of Aix-la-Chapelle in 1748 British colonial conquests were exchanged for a French withdrawal from Brussels. Many saw this as merely an armistice and awaited an imminent new war. Dispute with Newcastle In 1754, Henry Pelham died suddenly, and was succeeded as Prime Minister by his brother, the Duke of Newcastle. As Newcastle sat in the House of Lords, he required a leading politician to represent the government in the House of Commons. Pitt and Henry Fox were considered the two favourites for the position, but Newcastle instead rejected them both and turned to the less well-known figure of Sir Thomas Robinson, a career diplomat, to fill the post. It was widely believed that Newcastle had done this because he feared the ambitions of both Pitt and Fox, and believed he would find it easier to dominate the inexperienced Robinson. Despite his disappointment there was no immediate open breach. Pitt continued at his post; and at the general election which took place during the year he even accepted a nomination for the Duke's pocket borough of Aldborough. He had sat for Seaford since 1747. The government won a landslide, further strengthening its majority in parliament. When parliament met, however, he made no secret of his feelings. Ignoring Robinson, Pitt made frequent and vehement attacks on Newcastle himself, though still continued to serve as Paymaster under him. From 1754 Britain was increasingly drawn into conflict with France during this period, despite Newcastle's wish to maintain the peace. The countries clashed in North America, where each had laid claim to the Ohio Country. A British expedition under General Braddock had been despatched and defeated in summer 1755 which caused a ratcheting up of tensions. Eager to prevent the war spreading to Europe, Newcastle now tried to conclude a series of treaties that would secure Britain allies through the payment