Francisco de Aguirre was the son of Hernando de la Rúa and of Constanza de Meneses. He joined the army of Carlos I, participating in the Battle of Pavia and the assault on Rome in 1527. While in Rome as an Alférez in 1517, he was charged with the protection of a convent and as a reward, the Pope allowed him to marry his cousin, María de Torres y Meneses, while the King appointed him Corregidor of Talavera de la Reina.