Mackenna, John [Juan] (1771-1814), general in the Chilean war of independence, born on 26 October 1771 in Clogher, County Tyrone, the son of William McKenna and Eleanor O'Reilly. John Mackenna went to Spain with his uncle Count O'Reilly, and studied at the Royal School of Mathematics in Barcelona. In 1787 he was accepted into the Irish Brigade of the Spanish army, and joined the army fighting in Ceuta in northern Africa. Lieutenant Colonel Luis Urbina promoted him to Second Lieutenant. In 1791 Mackenna resumed his studies in Barcelona and acted as liaison with mercenaries recruited in Europe. The following year he was promoted to Lieutenant in the Royal Regiment of Engineers. In the war against the French, John Mackenna fought in Rosellón under General Ricardos and met the future liberator of Argentina, José de San Martín. For his exploits in defence of the Plaza de Rozas, he was promoted to captain in 1795.

For the purpose of a new assignment, in October 1796 John Mackenna left Spain for South America. He arrived in Buenos Aires and then travelled to Mendoza and to Chile across the Andes. Once in Lima, the viceroy Ambrose O'Higgins appointed Mackenna as governor of Osorno. In this capacity, John Mackenna convinced the families of Castro, on the island of Chiloé, to move to Osorno to found a colony there. He built the storehouse and two mills, as well as the road between Osorno and present-day Puerto Montt. His successful administration provoked jealousy from Chile's captain-general Gabriel de Avilés, who feared that John Mackenna and Ambrose O'Higgins would create an Irish colony in Osorno. Both Irishmen were loyal to the Spanish crown, though John Mackenna had good relations with O'Higgins' son Bernardo, the future emancipator of Chile, and was also connected with the Venezuelan Francisco de Miranda and his group of supporters of South American independence. When Ambrose O'Higgins died in 1801, Avilés was appointed viceroy of Peru. It took him eight years to remove O'Higgins's protégé John Mackenna from Osorno.

In 1809 John Mackenna married Josefina Vicuña y Larraín, an eighteen-year-old Chilean woman from a family with revolutionary connections. The following year he was called to the defence committee of the new Republic of Chile, and in 1811 was appointed governor of Valparaíso. Owing to political feuds with José Miguel Carreras and his brothers, John Mackenna was dismissed from the post and taken prisoner. He supported the faction of Bernardo O'Higgins, who appointed him as one of the key officers to fight the Spanish army of General Antonio Pareja. Mackenna's major military honour was attained in 1814 at the battle of Membrillar, in which the general assured a temporary collapse of the royal forces. He was appointed commandant-general by Bernardo O'Higgins, but after a coup d'état led by José Luis Carreras both were banished to the Argentine province of Mendoza. John Mackenna died on 21 November 1814 in a duel with José Luis Carreras in Buenos Aires.

Edmundo Murray

References

- Tellez Yañez, Raúl. El General Juan Mackenna: Héroe del Membrillar (Ensayo histórico) (Santiago: Alonso de Ovalle, 1952).

- Vicuña Mackenna, Benjamín. La guerra a muerte: memoria sobre las últimas campañas de la Independencia de Chile, 1819-1824 (Santiago: Imprenta Nacional, 1868).