At the age of 14, because of illness, he left Buenos Aires to live in the pampas, where he learned the ways of the gauchos. From 1853 to 1868 he took part in the provinces' political struggle with Buenos Aires. After the unsuccessful revolt against Pres. Domingo Sarmiento's government in 1870, Hernández fled to Brazil (January 1871). On returning to Buenos Aires, he published El gaucho Martín Fierro (1872; The Gaucho Martin Fierro, 1974), a work depicting the life of a persecuted gaucho; it is recognized as the best example of gaucho poetry. In the poetic narrative's second part, La vuelta de Martín Fierro (1879; “The Return of Martín Fierro”), the gaucho hero is reintegrated into the society he had abandoned.