Originally a law student at the University of Santiago de Compostela, he enlisted in the Spanish army and went to Peru in 1817 as one of the commissioned officers in the fight against the pro-independence nationalist forces.

He led the Carabineros Corps, established by a royal decree issued by King Fernando VII in 1829 at the time that Luis López Ballesteros was Minister of Finance.

Shortly after the last evacuation of Lima by the Royalist Army troops, the pro-independence soldiers finally took the capital, with Bolívar's arrival causing a massive exodus to Callao of those who maintained their loyalty to the Spanish crown, either by sincere conviction, for the defense of their interests, or for subsequent lawsuits with the leaders of the young independent Peru, with various Spaniards, Creoles, and mestizos fleeing as refugees.

Now besieged by nationalist forces backed by Simón Bolívar, Rodil refused to surrender, even as scurvy and starvation wreaked havoc among the hundreds of loyalists living in the fort.

[3] Despite being informed in January 1825 about the capitulation at Ayacucho and its terms, this Spanish chief rejected the surrender proposal and insisted on defending Callao, hoping at some point to receive military reinforcements from Spain that never arrived.