On 13 Aug., however, he joined Henry at Hardelot Castle, near Boulogne, and was present at the capture of that town on 14 Sept. Hertford, indeed, is said to have bribed the French commander De Vervins to surrender the town for a large sum of money (Mémoires du Maréchal de Vieilleville, ed. 1822, i. 152–3; Nott, Surrey's Works, p. lxix). Five days later Charles V secretly concluded the peace of Crêpy with the French, leaving his English allies still at war, and on 18 Oct. a conference was opened at Calais by the three powers to arrange terms. Hertford was the principal English representative, but no results followed, and on the 26th he and Gardiner were despatched to Brussels to endeavour to extract a definite declaration of policy from the emperor (State Papers, x. 63–6, 119–36, 147–50; Addit. MS. 25114, ff. 312, 315). After much procrastination, Charles granted them three interviews, the last on 17 Nov.; but their efforts to keep him to the terms of his alliance with England were unavailing, and on the 21st they were recalled (State Papers, 202–7 et sqq.). England now made preparations to carry on the war single-handed. On 14 Jan. 1544–5 Hertford was sent to survey the fortifications of Guisnes, and a few days later he took command at Boulogne, which the French made a desperate effort to recapture. On 26 Jan. Marshal De Biez encamped before it with fourteen thousand men, while those at Hertford's command were but half that number. Nevertheless, before dawn on 6 Feb. the English sallied out with four thousand foot and seven hundred horse, and took the French by surprise. A panic seized them, and they fled, leaving their stores, ammunition, and artillery in the hands of the English (Herbert, Life and Reign of Henry VIII, ed. 1719, p. 250).
This brilliant exploit rendered Boulogne safe for the time, but the defeat at Ancrum Muir, on 17 Feb., decided Henry to send Hertford once more to the Scottish border. On 2 May he was appointed lieutenant-general in the north in succession to Shrewsbury (Rymer, xv. 72), but, owing to the smallness of his force and lack of supplies, Hertford suggested a postponement of the projected invasion until August. Throughout the summer he remained at or near Newcastle, providing against the contingency of a Scots or French invasion. At length, on 6 Sept., he crossed the border; on the 13th he was at Kelso, and a few days later at Jedburgh. A list, which he sent to the government, of monasteries and castles burnt marks his course. He met with no opposition; but his invasion was only a border foray on a large scale, and on the 27th he was back at Newcastle (State Papers, v. 448–52; Hamilton Papers, vol. ii.). On 10 Oct. he received a summons to parliament, which met in November, and on the following day he set out for London. From the 24th until the following March he was in attendance at the council. On 21 March he was appointed lieutenant and captain-general of Boulogne and the Boulonnois in succession to Surrey, who had failed to hold his own against the French. He reached Calais on the 23rd (State Papers, xi. 60), and on 4 April was commissioned lieutenant-general of the army in France. In the same month he was appointed to treat for peace, which was concluded on 7 June. On the 31st he was again in London. On 19 Sept. he was once more sent to Boulogne to carry out the terms of the destruction of the fortifications (De Selve, Corr. Politique, 1888, pp. 31, 34; State Papers, i. 877, 879); but in October he was back at Windsor (Acts P. C., ed. Dasent, i. 535). From that time to the end of Henry's reign Hertford was constant in his attendance at court and council.
These few months witnessed the momentous struggle for the succession to power during the coming minority of Edward VI. The numerous attainders of Henry's reign had left Norfolk and Hertford face to face as the most powerful nobles in the kingdom. The former, with his son Surrey, headed the conservative party, while Hertford, though he was far too cautious to give open expression to his views, was known to favour further steps in the direction of ecclesiastical reform. This divergence of view was accentuated by personal jealousy between Surrey and Hertford, who had recently been called in to retrieve his rival's military blunders. Surrey vowed vengeance, and, hating Hertford as an upstart, he rejected his father's proposals for matrimonial alliances between his children and Hertford's two daughters, as well as between the Duchess of Richmond and Hertford's brother Thomas. The hope of conciliation thus failed, but the struggle between the rivals, which might have led to civil war, was averted by the dramatic fall of the Howards in January 1546–7 [see Howard, Henry, Earl of Surrey, (1517?–1547), and Howard, Thomas II, Earl of Surrey, (1473–1554)]. Hertford took an active part in Surrey's trial (Wriothesley, Chron. i. 177; Bapst, p. 358); he was commissioned to convey Henry's assent to the bill of attainder against Norfolk, and he acquired a share of the Howards' property; but there is not sufficient evidence to show that their fall was due to his machinations,
