In the summer of 1690, the regiment had the honour to serve at the battle of the _Boyne_, under the eye of its Sovereign, who commanded the army in Ireland in person; and on this occasion it took part in forcing the passage of the river, and in gaining a decisive victory over the army of King James on the 1st of July. Advancing from the field of battle towards Dublin, the regiment was reviewed by King William at Finglass, on the 8th of July, and mustered six hundred and twenty-eight rank and file under arms. It was afterwards detached, under Lieut.-General Douglas, against Athlone; but that fortress was found better provided for a siege than had been expected, and the regiment rejoined the army. The TWENTY-SECOND was one of the corps employed at the siege of _Limerick_. Many things combined to prevent the capture of that fortress until the following year, and when the siege was raised, the regiment proceeded into winter-quarters, from whence it sent out detachments, which had several rencounters with bands of armed peasantry, called Rapparees. [Sidenote: 1691] On the 6th of June, 1691, the regiment joined the army commanded by Lieut.-General De Ghinkel (afterwards Earl of Athlone) on its march for _Ballymore_, which fortress was speedily forced to surrender. From Ballymore, the regiment marched to _Athlone_, and had the honour to take part in the siege of that fortress, which was captured by storm on the 1st of July. The grenadier company of the regiment formed part of the storming party, which forded the river Shannon under a heavy fire, and carried the works with great gallantry. The capture of Athlone is one of the many splendid achievements which have exalted the reputation of the British arms, and its reduction proved a presage of additional triumphs. Astonished and confounded by the capture of Athlone, General St. Ruth retreated, with the French and Irish army under his orders, to a position at _Aghrim_, where he was attacked on the 12th of July. On this occasion, the regiment formed part of the brigade commanded by its Colonel, Brigadier-General Sir Henry Bellasis, and it contributed towards the complete overthrow of the army of King James, which was driven from the field with severe loss, including its commander, General St. Ruth, who was killed by a cannon-ball. The regiment had one Ensign and two private soldiers killed; one Major, and twenty-three soldiers wounded. On the 19th of July the army approached _Galway_; after sunset six regiments of foot and four squadrons of horse and dragoons passed the river by pontoons, and on the following morning they captured some outworks. On the 21st the garrison surrendered. Brigadier-General Sir Henry Bellasis was nominated Governor of Galway, and he took possession of the town with the TWENTY-SECOND and two other regiments of foot.