He entered as a novice at the Augustinian Convent in Salamanca, where he took vows in 1615. He was a prior of his order in several monasteries and became a master of his order. He was nominated as chronicler of Galicia in 1656 by the governing body of the Galician Kingdom.
These are his most important books: Epitome imperial (a work on Galician history), Armas, Triunfos y hechos heroicos de los hijos de Galicia (1662), which praises the services of the Galician Kingdom in the war against Portugal, (1640-68), Nobiliario, Armas y triunfos de Galicia (1967), and El cisne Oriental canta las palmas y triunfos eclisiásticos de Galicia (1677, two volumes). He also wrote Varones ilustres; Origen y antigüedad de la Casa de Ola.
He was the first historian who considered Galicia as a historical unit and was fully aware of the personality of his region.