Juan Gregorio de las Heras Grand Marshal Juan Gregorio de Las Heras ( July 11 , 1780 – February 15 , 1866 ) was an Argentine soldier who took part in the Spanish American wars of independence and was also a governor of the province of Buenos Aires . Biography . Las Heras was born in Buenos Aires , from a moderately wealthy family . He engaged in business till the age of twenty - six , when he enlisted in the army , taking part in the resistance against the British invasions of the Río de la Plata ( 1806 – 1807 ) . In 1808 he became sergeant of hussars . When the 1810 May Revolution took place , he acted with the patriots . He was appointed captain of militia in Córdoba , and in 1812 he became commander of the garrison of that city . In 1813 he offered to accompany the auxiliary Argentine division sent to Chile , of which he became second in command . After the Battle of Cucha Cucha he attained the rank of colonel , and after the defeat of Rancagua ( 2 October 1814 ) he retired in good order and twice repulsed the enemy , returning to Mendoza , where he employed himself in the organization of the Army of the Andes . On November 8 , he was appointed as the first commander of the newly created 11th Line Infantry Regiment . Created at the proposal of General San Martín to the Government , during the organization of the Army of the Andes and using the Chilean Auxiliaries as the foundation . This was the same infantry corps that had been sent to Chile in 1812 , commanded by then Lieutenant Colonel Las Heras to assist the Government Junta to face the invasion of the Royalists in Southern Chile . The Auxiliaries received their baptism of fire in the Battle of Cucha Cucha on February 23 , 1814 , and fought successfully for a second time in Membrillar on May 20 . After the important Spanish victory in Rancagua in October , they were charged with covering the retreat of their Chilean comrades and their government to the city of Mendoza . In 1815 , the 11th Line had the first regimental band of the Army of the Andes , thanks to the economic support of Rafael Vargas , a rancher from Mendoza . When the Army moved to Chile in 1817 , the regiment crossed the mountain range using the Uspallata pass , always commanded by Las Heras . After contributing to winning the Battle of Chacabuco , he headed the South Division , that was involved in a night battle on April 4 in Curapaligüe and on May 5 in Gavilán , two resounding victories . It also took part in the failed assault on Talcahuano , December 6 . On April 5 , 1818 , the 11th Line fought heroically in the Battle of Maipú , which sealed the freedom of Chile . It was created once again in 1885 and sent to hold positions in the frontier of the territories occupied by wild Indians , such as Tapalqué , Olavarria and Tres Arroyos , in the Province of Buenos Aires . In 1910 the President of Argentina , José Figueroa Alcorta , issued a decree to rename it 11th Infantry Regiment " General Las Heras " in honor of its first commander . Currently , the 11th Mountain Infantry Regiment is headquartered in Tupungato , Province of Mendoza . In 1817 , Las Heras took charge of a part of the Army of the Andes , replacing Antonio González de Balcarce . Leading one column by the pass of Uspallata , he commanded in the battles of Potrerillos , Guardia , and Villa de los Andes . Together with the forces of General San Martin he took part in the Battle of Chacabuco , ( 12 February 1817 ) , and immediately afterward was sent to the south , where he gained the victories of Curapalihue , Vegas de Talcahuano , and Oavihm , and was present at both of the sieges of Talcahuano under the orders of General Bernardo O ' Higgins . He also participated in the liberating expedition to Peru . Transported by sea , the Regiment disembarked in Peru in September 1820 , where it was involved in the battles of Nazca , Acarí and Jauja and in the siege and occupation of Lima on July 9 , 1821 , as well as in the surrender of the fort of El Callao on September 21 . In 1824 the 11th Line was disbanded . In 1820 he was chief of staff of the liberating army of Peru , and in the same year was promoted to brigadier by the Argentine government , and general of division by the Chilean government . In Peru he had the command of the siege of the castles of Callao and received the title of Grand Marshal . After his retirement from the Army in Peru , he went back to the Argentine Republic , where Las Heras was appointed governor of Buenos Aires by the Chamber of Representatives , succeeding General Martín Rodríguez in May , 1824 . During his government the congress of the United Provinces of the Río de la Plata met on 16 December 1824 , and Las Heras signed an international treaty by which the Britain acknowledged the Argentine independence . On the restoration of the confederation and the election of Bernardino Rivadavia to the executive , Las Heras delivered the government to him on March 7 , 1825 , and in 1826 he returned to Chile . He was deprived of his rank on account of his participation in the Chilean Civil War of 1829 , but the rank was restored by the Chilean Congress in 1842 and by the Argentine congress in 1855 . From 1862 till the time of his death he was inspector - general of the Chilean Army . Las Heras died in Santiago in 1866 , at the age of 85 .