This officer entered the army on the 28th of April 1783, as Ensign in the One hundred and fifth regiment, which was disbanded in the following year, and on the 12th of February 1793, was promoted to the rank of Lieutenant in the Fifty-ninth regiment, from which he was removed to the Fourteenth foot on the 7th of March following, and to the Ninety-first regiment on the 30th of October of the same year. Lieutenant Doyle served with the Fourteenth regiment until the beginning of 1794, in Holland and Brabant. In the assault of the heights of Famars in 1793 he acted as Brigade-Major to the brigade under Lieut.-General Sir Ralph Abercromby, whose thanks he received upon the field of battle for his conduct in storming the redoubts upon the heights over Valenciennes. During the siege of that city Lieutenant Doyle was employed as orderly officer in attendance upon the Austrian generals. While on service in the trenches he received a contusion in the head from the splinter of a shell. The Fourteenth regiment having suffered considerably, was left to garrison Courtray. He obtained permission to join the army, and served the remainder of the campaign as Aide-de-camp to Lieut.-General Sir Ralph Abercromby, by whom he was sent to the Duke of York with the account of the affair at Lannoi, in which he received a contusion in the hand, and was again thanked upon the field of battle by Lieut.-General Sir Ralph Abercromby. On the 21st of June 1794, Lieutenant Doyle was promoted from the Ninety-first, in which he had acted as Adjutant, to the Captain-Lieutenancy and Adjutancy of the One hundred and eighth regiment; proceeded to Gibraltar, where, upon that corps being drafted, he was appointed Aide-de-camp to the governor of that fortress. On the 3rd of September 1795, he was removed to the EIGHTY-SEVENTH, as Captain-Lieutenant and Adjutant, and embarked in 1796 as Brigade-Major to the expedition against the Texel, under his uncle Brigadier-General John Doyle. In that year Captain Doyle proceeded to the West Indies in the same capacity, but finding that his regiment was destined to attack Porto Rico, he resigned his staff situation, accompanied the EIGHTY-SEVENTH, and received the thanks of Sir Ralph Abercromby for his conduct in covering the retreat of the army in April 1797, and was appointed his Aide-de-camp. In 1798 he received the thanks of the Governor of Barbadoes, for having driven off the coast a large French privateer. Captain Doyle proceeded as Brigade-Major under General Sir Ralph Abercromby with the expedition for the attack of Cadiz in 1800; sailed from Minorca for the relief of Genoa, and from Malta proceeded to Egypt, where he served upon the staff of the army during the campaign. While suffering from illness at Rosetta, in consequence of a wound he had received in the battle of the 21st of March 1801, near Alexandria, he obtained precise and important information regarding the strength of the garrison and the state of the works at Cairo, which