One of the most colourful figures of the Wild Geese, who left Ireland to offer service in foreign armies, is Alejandro O’Reilly.

An undoubtedly brave and intelligent military strategist, O'Reilly rose through the ranks and left a lasting impact on the history of warfare.

He is also a complex and polarising figure, remembered in history by many as the “Bloody O’Reilly” for his ruthless behaviour as the Spanish governor of Louisiana.

Alexander, later Alejandro, O’Reilly was born in October 1723 in Baltrasna, Co Meath.

His family had a long and proud military history. His grandfather John O’Reilly led his regiment ‘Reilly’s Dragoons’ in the service of King James the 2nd at the siege of Derry.

His father Thomas married Rose McDowell from Co Roscommon. They went on to have four children, the youngest of whom was Alexander who would go on to be known as Alejandro when the family fled to Saragossa in Spain where the children were educated.

Alejandro O’Reilly joined the Spanish army at just 11 years old, serving as a cadet in the famous Hibernia regiment that had been formed in 1710.

In 1739, he was promoted to sub-lieutenant at the outbreak of the War of the Austrian Succession.

The Hibernia regiment was soon heavily involved in the fighting. O'Reilly's bravery and intelligence began to be noticed and he was promoted to infantry lieutenant. At the battle of Campo Santo in Italy, he was badly wounded and lay overnight on the battlefield with the other wounded and dead. As dawn broke, he was found alive by an Austrian soldier and only escaped being bayoneted by convincing him that he was from a wealthy family and worth a ransom!

A stroke of luck saved his life. Taken before the Austrian leader, he was spared because the military commander was another Irishman by the name of Browne. He had O’Reilly’s wounds tended to and returned him to the Spanish side. O'Reilly, however, was left with a permanent limp as a result of his wounds.

When a peace treaty was signed, O’Reilly returned to Spain as third in command of the Hibernia regiment. He immediately petitioned the Spanish king for a temporary transfer to the Austrian army, no longer at war with Spain to learn their military tactics.

In 1757, he transferred to the Austrian army where he distinguished himself against the Prussians at Hochkirchen in 1758. The following year, he entered French service and assisted at the battle of Bergen in 1759 and the taking of Minden and Corbach.

After war broke out between Spain and Portugal, he re-entered the Spanish service. He was made lieutenant general and defeated the Portuguese at Chaves in 1762.

In 1763, O'Reilly reorganised the Spanish forces and administration in Cuba. The old soldier even found love married into a prominent Cuban family.

In 1765, he saved the life of the Spanish King Charles III during a riot in Madrid. Later that year, O'Reilly went to Puerto Rico to assess the state of the defences in the colony; he is still known today as the ‘father’ of the Puerto Rican militia.

In 1769, O'Reilly was sent to Louisiana, then a Spanish colony, where a rebellion by French settlers had broken out. The insurrection had been instigated by the French government forcing the Spanish administration to flee.

O’Reilly was given explicit instructions to quell the revolt using whatever means he felt fit.

He ruthlessly suppressed the uprising executing five of the ring leaders earning himself his reputation as the “Bloody O'Reilly."

On his return in 1771, as a reward he was ennobled as a Spanish count

In 1775, he was appointed to lead the Spanish assault on Algiers. Despite meticulous planning and a force of over 20,000 troops, the campaign would end in disaster. Spies gave the defenders forewarning and the Spanish forces were repelled by heavy artillery.

The failure led the poet Lord Byron to write of him “Count O’Reilly did not take Algiers … but Algiers very nearly took him."

After a brief period of banishment, but still valued by the Spanish King for his administrative skills in 1776 he was appointed captain general of Andalucia and governor of Cádiz.

While living in semi-retirement, he was once again called upon by the Spanish in their hour of need to lead Spanish forces in defense of Royalists after the French Revolution. He left Madrid in 1794. Now in his late seventies, he was in ill health and suffered a heart attack and died in the village of Bonete near Albacete Jovellanos on March 23.

Alejandro O’Reilly remains a complex and polarising figure. While he may have been remembered as the “Bloody O’Reilly” for his brutal tactics and ruthless behaviour, there is no denying his impact on the Spanish military and his role in shaping the course of warfare in the 18th century.

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