His parents were Manuel Saavedra Cabrera, son of the president of the First Government of Buenos Aires in 1810 and Argentine general, Cornelio Saavedra, and Josefina Rodriguez Salcedo. He married Dorotea Rivera Serrano, daughter of Chilean General Juan de Dios Rivera and Freire de Andrade and Galeazzo Maria del Rosario Alfaro Serrano. At the age of 15 years he entered the military academy, graduating with the rank of second lieutenant of infantry in the Chilean Army in the following year. In 1837 he was assigned to Battalion Chillán, where he rose to lieutenant at the age of 17 years. In 1847 he was promoted to the rank of sergeant major and retired from active duty for health reasons in 1849. Two years later he was called to participate in the 1851 Revolution to overthrow the newly elected President Manuel Montt and to repeal the 1833 Constitution. In 1857 he was appointed mayor and commander of weapons of Arauco, in whose care had to quell the uprising of the southern provinces during the revolution of 1859. That year he was reinstated to the Army with the rank of sergeant major. Cornelio Saavedra Rodríguez took office as General Commander of the Chilean Navy in 1860, but left the charge the same year. In 1862 he was promoted to lieutenant colonel.