There is a statue commemorating his bravery in Fitzgerald Park in Cork City where he was born, but many Cork residents today have no idea who he was. Yet history students in Venezuela know him as one of the most trusted aides of Simon Bolivar, the liberator of what is today Venezuela, Colombia, Panama, Ecuador, Peru and Bolivia.

Daniel Florence (Florencio) O'Leary was born in 1801, the son of Jeremiah O'Leary and Catherine Burke. That the family's roots sprung from West Cork is certain. Unclear is precisely from what town. Some say they came from Inchigeela and others from Dunmanway. Once his great grandfather moved the family into Cork City, they became successful butter merchants utilizing their West Cork contacts to supply them with the products to sell in the city. The business was passed down to Daniel's grandfather and then to his father. But in the early 1800's after the Napoleonic War ended, the business declined substantially and young Daniel, by then in his mid teens, had to look for other opportunities.

Between 1817-1819 a recruitment campaign was underway which enlisted some 6000 English, Scottish and Irish volunteers for military service in Simon Bolivar's army to liberate South American territory from Spain. Daniel enlisted but by the time his group arrived on the shores of present day Venezuela, he became disillusioned by the poor quality of many of his fellow recruits who were veterans of Napoleonic era European armies seeking action as mercenaries. Daniel took the first opportunity to transfer to another regiment where he was soon spotted by Bolivar for his leadership and language abilities. He was quickly promoted up the ranks and gained the confidence of Bolivar. He was slightly wounded at Pantano de Vargas in July 1819, but recuperated sufficiently to participate in the battle of Boyaca in early August, which was a turning point in the liberation of Nueva Granada from the Spaniards. By this time he had become Bolivar's edecán or top assistant.

As Bolivar's trusted aide, O'Leary saw action in the more important battles at Carabobo in which Venezuela was liberated, and at Pinchincha bringing liberation to Ecuador. Bolivar's dream was to unite all the liberated territories into one large entity which he called Gran Colombia. But once liberation had been accomplished, the various parties began their own disagreements and little wars among themselves. Bolivar sent O'Leary as conciliator to try to resolve some of these differences but after Bolivar's death in 1830, one by one the individual territories each declared their own independence to become the countries of northern South America as we know them today.

In 1828 O'Leary married Soledad Soublette, the sister of Carlos Soublette, one of Bolivar's generals who later became president of Venezuela. After Bolivar's death in 1830, and because of the toxic atmosphere that had developed as a result of the disintegration of Gran Colombia, O'Leary and his wife moved to the island of Jamaica. Here he tried to set himself up as a merchant without much success. In Jamaica his wife gave birth to their first child. By 1833, his brother-in-law summoned them back to Venezuela.

O'Leary's fame as a conciliator developed into his being named diplomat by the Venezuelan government. By the mid-1830's he was appointed emissary seeking diplomatic recognition for Venezuela in the major capitals of Europe. His efforts took him on a five-year sojourn returning to South America in 1839. In the 1840's he was designated as the British government representative in Caracas and Bogotá.

In 1852, by now in declining health, O'Leary made another trip to Europe seeking medical care. His trip took him to London, Paris and Rome. On his way back, he visited his native Cork. Shortly after his return home to Bogotá, on February 24, 1854 he died. He was initially buried there but later his body was transferred to the National Pantheon in Caracas, where he was laid to rest close to the body of Simon Bolivar, the great Liberator.

 Perhaps the most long lasting piece of Daniel O'Leary's legacy was the voluminous work he wrote recounting his military campaign years. He used his own diaries and many of Bolivar's own letters and writings, to put together in 32 volumes what has been recognized as the most comprehensive history of Bolivar's life and times. Today there is a copy of the Memorias del General O'Leary in the University College Cork library.