Queen Sancha chose the new monastery as the site of the royal burial chapel. Today eleven kings, numerous queens and many nobles lie interred beneath the polychrome vaults of the medieval "royal pantheon". In 1063 the relics of Saint Isidore were transferred to the chapel, and a community of canons was established to maintain the monastery and ward the relics. The apse and transept of the building are in the Gothic style, whilst other parts of the building are Romanesque or of the Renaissance period.