second son had died in infancy—of George II, then prince of Wales, by Caroline, daughter of John Frederic, margrave of Brandenburg-Anspach. On 27 May 1725, when the order of the Bath was revived, he was nominated first knight, and on 15 July 1726 he was created Baron of Alderney, Viscount Trematon, Earl of Kennington, Marquis of Berkhampstead, and Duke of Cumberland. He was made knight of the Garter on 18 May 1730, and installed on 18 June.
Gay's fables were ‘invented to amuse’ the young duke in 1725–6. Jenkin Thomas Philipps [q. v.] was his tutor, and seems to have found him an apt pupil (see No. 8 of his Easy and Elegant Latin Letters); Stephen Poyntz [q. v.] was governor and steward of his household, and he often stayed at Poyntz's house at Midgham. William was the favourite of his parents, and they wished him to be lord high admiral. He was therefore educated for the navy, but his own tastes were military. In 1740, when Sir John Norris (1660?–1749) [q. v.] was ordered to intercept the French and Spanish fleets, ‘The Duke,’ as he was habitually called, even in the ‘Army List,’ joined the flagship as a volunteer, and served on board for some months. But the fleet was windbound in the Channel, and he made no further trial of a naval career.
An act of parliament had been passed on 14 June 1739 empowering the king to settle on him an income of 15,000l. a year from the civil list. On 23 April 1740 he had been made colonel of the Coldstream guards, and on 18 Feb. 1741–2 he was transferred to the 1st guards. When he came of age, on 15 April 1742, he took his seat in the House of Lords, and on 17 May he was sworn of the privy council. On 31 Dec. he was promoted major-general.
In April 1743 he accompanied the king to Hanover, and in June they joined the allied army on the Main. At the battle of Dettingen he was on the left of the first line of infantry, and, as Wolfe wrote, he ‘behaved as bravely as a man could do. He had a musket-ball through the calf of his leg. … He gave his orders with a great deal of calmness, and seemed quite unconcerned’ (Wright, p. 46). When the surgeon was about to dress his wound, the duke told him to attend first to a French officer near him whose wound was more serious, and who was more likely to be neglected. He was promoted lieutenant-general on 28 June.
Early in 1745 it was proposed that he should marry a deformed Danish princess. He was very unwilling, and consulted Lord Orford (Sir Robert Walpole), by whose advice he gave his consent on condition of receiving an ample and immediate establishment. As Walpole foresaw, the project was dropped (Reminiscences of Horace Walpole, Letters, vol. i. p. cxxxvii).
He had asked leave to serve in the campaign of 1744 in any capacity, but his request was rather sharply refused. When General George Wade [q. v.] resigned the command of the British troops at the end of that year, the king wished to appoint John Dalrymple, second earl of Stair [q. v.]; but Stair refused to serve under Marshal Königsegg, who was to represent Austria. The inconvenience of co-ordinate commands had been abundantly shown; and by Chesterfield's dexterity at the Hague it was eventually arranged that the duke should have the honorary command of all the allied forces in the Netherlands, with Königsegg adlatus (Trevor Papers, pp. 109 &c.) On 7 March 1744–5 he was made captain-general of the British land forces at home and in the field, an office dormant since Marlborough's time. He left England on 5 April, and, after visiting the Hague, arrived at Brussels and assumed command on the 10th (21st N.S.)
A week later news came that the French army under Marshal Saxe had invested Tournay, and on the 30th the allied army advanced to raise the siege. Its nominal strength was over fifty thousand men, its effective strength about forty-three thousand. On 9 May, having taken ten days to march less than fifty miles, it found the French army drawn up in its front at Fontenoy, four miles east of Tournay. On the day before the duke had written: ‘I cannot bring myself to believe the enemy will wait for us. … I cannot come at any certain knowledge of the enemy's number; but I have concurring information that the body on this side the Schelde does not exceed thirty-one battalions or thirty-two squadrons’ (Foreign Office Papers). His information was bad. The whole French army consisted of 106 battalions and 162 squadrons, and of these 60 battalions and 110 squadrons, or about forty-seven thousand men, took part in the battle of Fontenoy, fought on 11 May.
It has been commonly said that Königsegg was against attacking the French in their prepared position; ‘but the ardent courage of the Duke of Cumberland and the confidence of the English would take no advice’ (Espagnac, i. 59). The despatches show that this was not the case; the allied generals were unanimous for attack (English Historical Review, xii. 528). In the battle the duke was far from being a mere titular chief. On the contrary, he tried to do too much.