The abbey was founded around 951 by Bishop Sisnando Menéndez, son of Counts Hermenegildo Alóitez and his wife Paterna, who in the following years give it several properties.

[2] Nearly two centuries later, in January 1142, the brothers Fernando and Bermudo Pérez, two of the most distinguished members of the House of Traba, handed it over to the Cistercian monks [3] from Clairvaux.

After a period of decline, in 1498 Sobrado was the first abbey in Galicia to join the Castilian Cistercian Congregation.

The dissolution of the monasteries enforced by the government of Mendizábal in 1835 put an end to the abbey, and the abandoned buildings fell into decay.

The present abbey church, now roofed with a number of domes and cupolas, was built at the end of the 17th century, although the Magdalene Chapel (Capela da Madalena or Capilla de la Magdalena) dates from the 14th century.