Colonel Dundas, having become a proficient tactician, produced, in 1788, a highly useful work on the principles of military movements, which became the basis of our army regulations for field exercises. His abilities obtained for him the favour and attention of King George III., who appointed him adjutant-general in Ireland, for the purpose of introducing his system of tactics into the army of that country. In 1790 Colonel Dundas was promoted to the rank of major-general. In 1791 he obtained the colonelcy of the twenty-second foot, and in the same year was placed on the Irish staff, but he resigned that appointment in 1793 to engage in service of actual warfare. After the commencement of hostilities with the French republic, Major-General Dundas was employed on a military mission to the island of Jersey, and was subsequently sent to the continent to confer with the Duke of York respecting the siege of Dunkirk. From Flanders he proceeded to Toulon, which had recently been taken possession of by a British armament; and his services there, although he was ultimately obliged to evacuate the place, called forth the approbation of his sovereign and of the British nation. After abandoning Toulon, he made a descent on Corsica, which island was reduced and annexed to the British dominions; but shortly afterwards he received directions to proceed to Flanders, where he arrived in the spring of 1794, and commanded a brigade of cavalry at the battle of Tournay on the 22d of May, 1794. Major-General Dundas was actively employed in the retreat through Holland, and the corps under his immediate command gained considerable advantage over the enemy in two successive actions near Gelder-Malsen; he highly distinguished himself also in an attack upon the French post at Thuyl, in December of the same year. He continued with the British troops in Germany during the summer of 1795, and in December was appointed colonel of the SEVENTH Light Dragoons. After his return to England he was appointed quarter-master-general to the army; and he composed the celebrated regulations for the field exercises and movements for the cavalry, which were approved by his Royal Highness the Duke of York and by King George III., and ordered to be exclusively adopted throughout the cavalry.