In April of the following year a further augmentation of nine men per troop was made to the establishment; and in 1742 a British army was sent to Flanders to support the pretensions of the Archduchess Maria-Theresa, as Queen of Hungaria, against the power of France and the Elector of Bavaria; but this regiment was detained in Ireland. In the beginning of 1743 the regiment furnished a draft of ten men and horses per troop to join the regiments of horse on foreign service.
Lieutenant-General Lord Tyrawley, after commanding the regiment nearly four years, was removed to the Colonelcy of the Second Troop of Horse Grenadier Guards, and the command of the Fifth Horse was conferred on Colonel John Brown from the Ninth Dragoons, his commission bearing date the 1st of April, 1743.
1744
In the beginning of the following year another draft of men and horses was sent on foreign service.
1745
In April, 1745, the regiment was reviewed at Maryborough by Major-General de Grangues; and after the rebellion headed by Charles Edward, eldest son of the Pretender, broke out in Scotland, this regiment was ordered to Dublin, and the army in Ireland was placed in dispersed cantonments near the coast to resist any descent which might be attempted upon the island.
1746
After the suppression of the rebellion in Scotland, three of the four regiments of Horse in England were reduced to the quality of Dragoons (25th December, 1746), and styled Dragoon Guards, and this regiment obtained the designation of the First Irish Horse. The regiments of horse on the Irish establishment (now the 4th, 5th, 6th, and 7th Dragoon Guards) were frequently designated by the colour of their facings; the First being frequently called the Blue Horse; the Second the Green Horse; the Third, the Carabiniers; and the Fourth the Black Horse.
1748
A treaty of peace was concluded with France and Bavaria at Aix-la-Chapelle in the winter of 1748-9; and, while the negociations were in progress, the establishment of the First Irish Horse (with that of all other regiments of horse and dragoons in Ireland) was reduced to twenty-one private men per troop.