ALEXANDER COUNT O'REILLY was born in Ireland about 1735, of Roman Catholic parents, and when young entered the Spanish service as a sub-lieutenant in the Irish regiment with which he served in Italy during the war of the Spanish Succession, and received a wound from which he was rendered lame for the rest of his life. In 1751 he went to serve in Austria, and made two campaigns against the Prussians, under the orders of Marshal Count Lacy, his countryman. Then in 1759 he passed into the service of Louis XV., under whose colours was still that celebrated Irish Brigade whose native bravery so mainly contributed to win for France the glory of Fontenoy. O'Reilly distinguished himself so much that the Marshal de Broglie recommended him to the King of Spain, with great warmth of expression, on his retiring to Madrid. The marshal's interest won him the rank of Lieutenant-Colonel, and as such he served in that war which conduced so little to the glory of Portugal, though favoured by the alliance of Britain. Nevertheless, O'Reilly found many opportunities for distinction at the head of the light troops which were confided to him, and soon won the proud reputation of being one of Spain's most gallant officers. He was now named Brigadier of the Armies of the King, with the post of _aide major de l'exercise_. In these capacities he drilled the Spanish infantry according to the best system of tactics and exercise then practised in the British service. At the peace he was appointed Mariscal de Campo, and named Commandant en Seconde of Havannah, which was to be given up to Spain by the treaty of Fontainbleau. On arriving there, he restored and strengthened the fortifications of the colony, and soon after returned to Spain, where the king named him Inspector-General of Infantry, and desired him to assist in the manoeuvres of a great camp, of which he gave him command. He then sent him to New Orleans, where the inhabitants had scarcely become accustomed to the Spanish yoke, and where the rigorous means employed by O'Reilly to subdue them gained him many enemies. The count returned again to Madrid, and was treated with every mark of favour by Charles III., who knew all his talents, capacity, and courage; and could never forget that it was to the strong hand and stout heart of O'Reilly he owed his life during the fiery sedition at Madrid in 1765, when the people rose in arms. Every honour Charles could bestow upon a foreigner was showered upon O'Reilly, who now gave the Spanish army (which was many years behind every other in Europe in the march of progression and improvement) a new spirit, vigour, and impulse. In this task he was assisted by his brother-in-law, Francisco Xavier Castanos, afterwards Duke of Baylen, Captain-General of Estremadura, Old Castile, and Galicia, whom he took with him to Prussia when he visited that country, like all the principal officers of Europe, to witness and examine the manoeuvres practised by the troops of the Great Frederick.