Rose’s father summed up his early life as follows:
At the head of Winchester school a year or two earlier than usual, he had an opportunity of spending eighteen months in Geneva, under the care of the ablest and most respectable men there, in attaining modern languages, acquiring the principles of the law of nations, &c, and then went to Cambridge at eighteen. As soon as he had taken his bachelor’s degree, he was placed under Lord Auckland at The Hague, with the privilege of seeing the whole correspondence of Europe, then passing through there, working at least ten hours a day, till Lord Grenville sent him to Berlin, with the charge of the King’s affairs, on the ground of the character he heard of him, without any application from me; and I had the satisfaction of being told repeatedly, by his lordship, that he was most entirely satisfied with him.
Rose Diaries, i. 439-40; ii. 361; Add. 34445, f. 95; 34451, f. 430; Auckland Jnl. iii. 17, 70.
After 13 months at Berlin, Rose returned home in poor health, whereupon his father secured his election to Parliament for Southampton. Four years before his father had written:
I have no intention of bringing him into Parliament now. There are many reasons which induce me not to think of the House of Commons at present. Hereafter he shall have a sure seat if it shall be proper for him to fill it.
His Cambridge tutor, noting his lack of interest in mathematics, had also doubted whether he would ‘make a good speaker. He does not want quickness of conception but he seems not to have the art of arranging his ideas to the greatest advantage.’
At the time of Pitt’s resignation in 1801 Rose had achieved little, though much had been prognosticated for him, not without malicious reference to his father’s supposed accumulation of sinecures for himself and his sons. On 9 Aug. 1797 the Morning Chronicle reproached Rose for having sent a poor labourer to gaol for saying ‘A whole nation ought not to be sacrificed to the folly or ambition of one man’. Subsequently he was the go-between in an attempted rapprochement between the Prince of Wales and Pitt. By the end of 1801 he wished to resume his diplomatic career and Lord Hawkesbury was approached by Pitt on his behalf. He was offered Stockholm or Copenhagen at once, with the prospect of Naples when vacant. He preferred to wait for the latter on climatic grounds. When the vacancy was imminent in the autumn of 1802, he declined it; following his father’s line over the treaty of Amiens, he could not honourably accept employment from Addington. He asked merely for a pass to go abroad. His father boasted that Rose had passed ‘a test of his sincerity’. He proceeded to Berlin with a train of servants.
Rose, who had survived a contest for Southampton in 1802, joined his father in opposing Addington on the defence motions that brought him down, 23, 25 Apr. 1804, and was listed an adherent of Pitt’s second ministry. His father applied on his behalf to Lord Harrowby, but he did not obtain a foreign embassy, only a deputy paymastership to his father. Like him he joined the majority for the additional force bill on 11 June after being absent on the 8th. The King, who approved his ‘perfect resemblance in mind’ to his father, looked forward to his obtaining a diplomatic post and his father made it clear to Pitt that Rose’s deputy office was at his disposal. Like him he swallowed Pitt’s reconciliation with Addington in December 1804. He voted in the government minority on Melville’s conduct, 8 Apr. 1805. A scheme of his father’s for him to accompany Lord Harrowby’s proposed embassy to Berlin late in 1805 came to nothing: Harrowby had already chosen George Hammond. His father had suggested to Pitt that Rose should hold no official appointment and that he would go only with Harrowby. Like his father he met with Pitt’s friends on 26 Jan. 1806 and voted against the Grenville ministry on Ellenborough’s seat in the cabinet, 3 Mar. 1806, dined with Pitt’s friends a week later and opposed the American intercourse bill, 17 June. He spoke against Windham’s military plan, 7 June, 5 July 1806. His father complained of ministerial hostility to his re-election at Southampton. He was listed ‘adverse’ to the abolition of the slave trade and voted against ministers on the Hampshire petition, 13 Feb. 1807. He was a defaulter on 2 Mar. and took a week’s leave on 15 Apr. Had Canning joined the Grenville ministry in March 1807, he thought Rose might have been placed at the Admiralty board.
On Canning’s appointment to the Foreign Office in 1807, Rose was offered a brief mission to Washington to parley with the United States government over the Leopard and Chesapeake incidents, 30 Sept. He arrived on 10 Jan. 1808 and left in April, having found his task impracticable; Lord Auckland had not thought him ‘an auspicious choice’. Rose hoped this was a stepping stone to further diplomatic employment, but in his hopes of Lisbon he was disappointed and his father declined applying to Canning any further after being reproached for bringing forward his son’s pretensions ‘on every occasion’. On he attempted to prove to the House that the American trade embargo was not in direct retaliation for the English order in council of 11 Nov. 1807, and on 6 Mar. explained his mission. On 1 Apr. his father suggested him to the Duke of Richmond as his chief secretary in Ireland, to which the duke apparently had no objection. But when Perceval became premier, a seat at the Treasury board was as much as he offered Rose, who disliked it because of the effect of parliamentary attendance on his health. Lord Bathurst was prepared to have him as his confidential secretary at the Foreign Office, which he first declined and then accepted; but this arrangement was stopped by the Marquess Wellesley’s taking over from Bathurst. Wellesley, applied to by his father, offered him Constantinople, which he declined ‘as I could not educate my numerous family there’.
When Rose’s father in March 1812 offered to resign at the end of the session, it was envisaged that he should eventually become paymaster-general, with a seat at the Treasury board in the meantime. In any case he was to succeed his father as vice-president of the Board of Trade and be a privy councillor. It was understood, however, that a diplomatic appointment remained his objective. All this came to nothing. When his father resigned the Board of Trade in September 1812, the only offer that had been made him was Lord Bathurst’s of under-secretary at the Home Office, with responsibility for the colonies. This would please his father by keeping him at home, without surrendering his diplomatic claims. But he declined (2 Aug.) because his health was not up to ‘the close confinement of such an office’. His father had intended him to give up Southampton for Christchurch at the ensuing election, but he did not do so. He was strongly challenged by a ‘radical reformer’ William Chamberlayne, and in December 1812 when Lord Liverpool offered him the government of the Ionian islands, he made the difficulty of securing that seat, which he would have to vacate, one of his reasons for declining.
On 23 Apr. 1813 Rose was offered Stockholm by Castlereagh and this time accepted, in the hope of a warmer post in due course; but he had apparently already conceded his willingness to go to Berlin. It was to Munich that he went, after all, in 1814 and thence to Berlin a year later. In 1816 he secured permission to return home at once if his father became seriously ill, but refusing to exchange Berlin for Naples, did not do so until his father’s death in January 1818. Succeeding his father as clerk of the Parliaments he was obliged to seek re-election. He had no hope at Southampton and transferred to his father’s seat for Christchurch.