Beauchamp continued to sit for the family borough of Orford and in the House acted from 1784 with opposition. He was among the Duke of Portland’s following who met at Burlington House, 11 May 1790. He at first continued in this line in the ensuing Parliament, voting against Pitt on the Oczakov question, 12 Apr. 1791. He was chairman of the committee on the English Catholic relief bill that month, as well as being listed favourable to repeal of the Test Act in Scotland. During the next session he was in France. Lady Sutherland reported from Paris, 27 July 1792: ‘I never saw a more laborious searcher for information ... it is question after question to everybody who will listen and answer, he is certainly a most indefatigable collector of facts’. In December 1792 he was listed as a Portland Whig and on 23 Dec. met with those of them who were anxious to induce the duke to break formally with Fox. He approved their measures and regretted the failure of the bid. On 4 Jan. 1793 he rose in the House in defence of the aliens bill, dissociating himself, at least on this occasion, from the Foxite opposition and adding that he had disapproved of Fox’s amendment to the address on 13 Dec. On 1 Feb. he seconded Pitt’s address to the King, the prelude to hostilities with France, in ‘a very decided speech’, arguing that the country had too long preserved its neutrality in the face of events across the Channel. Fox noted his defection in his reply, adding that ‘the noble lord’s attendance had not been very assiduous’ during their association of nine years ‘and he rejoiced to hear that the noble lord meant now to compensate for past omissions by future diligence’. On 22 Feb. Beauchamp defended the institution of barracks and on 22 Mar. the traitorous correspondence bill, refuting the comparison between the present war and that of 1756 and pointing out that the embargo on trade with France was merely retaliatory. He had attended the ‘third party’ meeting at Windham’s house on 10 Feb., and although he was absent on the 17th, re-emerged in May as one of the Windhamite political club.1PRO 30/29/5/4, f. 714; Malmesbury Diaries, ii. 483, 487, 492, 497; Geo. III Corresp. i. 831; Minto, ii. 139.
Beauchamp’s father became a marquess in July 1793 and he, by courtesy, Earl of Yarmouth. He had offered, 14 May, to make a ‘private excursion’ to the continent ‘subservient to any public issue’ and to go ‘to any part of the present theatre of the war’. He was sent, unsalaried, to the King of Prussia’s camp and, to recruit fighting men, to other German courts, remaining abroad until the end of the year. On 28 Jan. 1794, when he told the House that he claimed expenses only, there was nearly a fracas between Sheridan, who called for an explanation, and Pitt; three days later Yarmouth analysed the expenses for the House. He had been prepared to go on further missions; had asked for Switzerland and accepted Spain (where he had offered to go on 11 Nov. 1793) when, to Lord Malmesbury’s indignation he confronted him with his wish to replace him as envoy to Prussia, 5 Dec. Malmesbury made him climb down, noting that his character was ‘selfish, intemperate, cunning, and nervous, and with a fear to displease’: compare this with Thomas Pelham’s estimate a week later, ‘I always thought him pleasant and few people are better informed, but there is a want of energy in his character and a love of money that makes him insignificant and unpopular’. He then refused Spain and only a military mission, somewhat limited in its scope, was found for him.2PRO 30/8/144, f. 162; 193, ff. 1, 3; HMC Fortescue, ii. 399; Geo. III Corresp. ii. 899, 967, 1001, 1066; Malmesbury Diaries, iii. 17, 21; Add. 51706, Pelham to Lady Webster, 11 Dec. 1793; Glenbervie Diaries, i. 28.
In June 1794 Yarmouth succeeded to the marquessate and an income of over £70,000 p.a. When Pitt returned to power in 1804 he was made master of the Horse, an office he did not relinquish without a protest when relieved of it by the Grenville ministry. He was compensated in 1807 with the garter, not wishing to resume the office. By then his wife had acquired an ascendancy over the Prince of Wales which she retained until 1819: ‘the P[rince] got the Garter for the m[arques]s, and is to make him a duke’. He became lord chamberlain under the Regency. On resigning this office, 18 July 1821, he expected further reward, and applying for a dukedom, 2 Jan. 1822, suggested that his father had been promised one by Pitt ‘nearly 30 years ago’. It was refused, Lord Liverpool relieving George IV of the ‘delicate’ task of explanation. Hertford died 17 June 1822, an autocrat in his own family circle, and covetous, but otherwise ‘very attentive and obliging’: indeed, he had ‘a real passion for persons whom everybody else considers as bores’.3Geo. III Corresp. iv. 3182, 3416; Prince of Wales Corresp. viii. 3416; Geo. IV Letters, ii. 941, 988-9; Wraxall Mems ed. Wheatley, iv. 138; Croker Pprs. ed. Jennings, i. 126, 240; Farington, iv. 69, 191.