He joined the Spanish Army, and was a "maestre de campo" and a Lieutenant of the Cavalry Regiment of the Princess.

He was integral of the First Junta of the Government of the Kingdom 1810 to 1811, and one of the strongest proponents of the independence of the country.

He was part of the First National Congress of 1811 (July 4–20, 1811) as a deputy for Talca and Curicó, and was elected its vice president.

After the Disaster of Rancagua he didn't try to emigrate to Argentina, staying in Chile and being incarcerated on the Juan Fernández Islands.

Liberated from his captivity, he continued collaborating with the emancipation cause in Chile, integrating himself in 1818 to the Senado Conservador as a Senator, occupying the position until 1822.