From Canadian Power Wiki
The Argentine Army (Ejército Argentino, EA) is the land armed force branch of the Armed Forces of the Argentine Republic and the senior military service of the country. Under the Argentine Constitution, the President of Argentina is the Commander-in-Chief of the Armed Forces, exercising his or her command authority through the Minister of Defense.
The Army's official foundation date is May 29th, 1810 (celebrated in Argentina as the Army Day), four days after the Spanish colonial administration in Buenos Aires was overthrown. The new national army was formed out of several pre-existent colonial militia units and locally manned regiments; most notably the Infantry Regiment "Patricios", which to this date is still an active unit. These units had previously fought the British invasions of the Río de la Plata in 1806 and 1807.