1758
In 1758 the Second battalion was formed into the SIXTY-SIXTH regiment, under the command of Colonel Edward Sandford.
1759
1760
During the summer of 1759 the regiment was encamped at Brentwood, and in 1760 at Barham Downs.
1761
In 1761 the regiment was placed under the orders of Major-General Hodgson, for the attack of one of the French islands off the coast of Brittany, called Belle-Isle. The expedition appeared before this place on the 7th of April; but the whole island was found like one vast fortress, the little which nature had left undone by rocks and crags having been supplied by art; and the first attempt on the 8th of April, to establish a post on the island, failed. The NINETEENTH, mustering eight hundred men, under Lieut.-Colonel Robert Douglas, evinced great gallantry on this occasion in the assault of the enemy's entrenchments on the shore; the officers and soldiers rushed to the attack with heroic bravery, but were unable to ascend the steep acclivity; they attempted to help one another up, under a heavy fire, but failed, and were ordered to re-embark.
The regiment lost Lieutenant Dougal Stuart, three serjeants, one drummer, and forty-seven rank and file killed; Major Lumisden, one serjeant, one drummer, and thirty-eight rank and file wounded; Lieutenants Scrymsour, Forbes, and Nugent, one serjeant, and eighty-nine rank and file prisoners, thirty of whom were wounded.
Another attempt was made on the 22nd of April, when Brigadier-General Lambert effected a landing on the rocks near Point Lomaria: the difficulty of mounting the precipice had made the enemy least attentive to that part. Beauclerk's grenadiers (NINETEENTH), with Captain Patterson of the regiment, gained the summit before the enemy saw what was intended, who immediately marched a body of three hundred men to attack them; the grenadiers maintained their ground till the remainder of Brigadier Lambert's troops got up. Three brass field-pieces were taken, and some wounded prisoners. Captain Patterson lost his arm, and the other casualties were about thirty men killed. The cannon was afterwards landed from the ships and dragged up the rocks; the lines which covered the town of Palais were captured; the siege of the citadel was carried on with vigour, and the garrison surrendered on the 7th of June. The conquest of the island was thus achieved, and the officers and soldiers taken prisoners re-joined their regiments.
1762
Returning from Belle-Isle when the capture of that island was completed, the regiment was stationed in England in 1762.