In the mean time Ireland had become the scene of conflict between the Roman Catholics and Protestants, and King James, having proceeded thither with a body of French troops, had reduced the greater part of that kingdom under his sway, and had maltreated the Protestants in various ways. In 1689 King William sent Duke Schomberg, with a body of troops, to aid the Protestants, and in 1690 His Majesty resolved to take the field in person. The QUEEN'S regiment of foot was selected to form part of the army in Ireland, and having embarked from Barnstaple in the middle of April, put to sea, but was driven by severe weather to Pembroke. Here the regiment remained about a week, and having again put to sea on the 30th of April, landed at Belfast on the 2d of May. King William arrived in Ireland on the 14th of June, and placing himself at the head of the army, advanced to the banks of the _Boyne_, on the opposite side of which river King James's army was formed in order of battle. At day-break on the morning of the 1st of July, the regiment was under arms, every man displaying a green branch in his hat, to distinguish him from the enemy, who wore pieces of white paper in their hats, and the cheerful countenances of the musketeers, pikemen, and grenadiers seemed to give presage of victory. About six o'clock the regiment, with the remainder of Brigadier-General Trelawny's brigade, forming part of the force under Count Schomberg and Lieut.-General Douglas, filed to the right, and having marched about two miles up the river, forded the stream between the King's camp and Slane bridge. Sir Neal O'Neal's regiment of Irish dragoons, in the service of King James, offered some opposition; but was speedily routed and its commanding officer was mortally wounded. After passing the river, Trelawny's brigade halted a short time until additional forces arrived; then advancing through corn fields, over deep ditches, and across a difficult bog, drove the enemy's left wing from its ground in a spirited manner, and forced it to make a precipitate retreat towards Duleek. When the enemy's left flank was thus turned, King William passed the river with the other divisions of his army, and King James's forces were overpowered and chased from the field. Thus a decisive victory was gained, and the troops halted during the night near Duleek. The regiment advanced with the army upon Dublin, and at the review at Finglass, on the 7th and 8th of July, it mustered (according to the official rolls) five hundred and fifty-three private men, besides officers and non-commissioned officers. The enemy having fled from Dublin, the regiment was stationed several weeks in garrison in that city, of which its colonel was appointed governor.