This Cistercian monastery was founded in 1187 by King Alphonse VIII and his wife Eleanor de Plantagenet, who are buried here with some of their descendants who so desired, which makes the Monastery a Royal Pantheon.
The first nuns came from the Monastery of Saint Mary of the Charity of Tulebras (Navarra), where the first female Cistercian monastery on the peninsula existed since 1157.
The abbess of Las Huelgas came to have such high autonomy and power that she was above the episcopal curia, depending directly on the Pope.
During the Middle Ages, such important ceremonies as proclaiming kings and arming knights were held in this monastery. Among the knights armed before being kings are Fernando III the Saint, Eduardo I of England, Alfonso XI of Castile, Pedro I of Castile (who was also born in the defensive tower of the building) and John II. The kings crowned here were Alfonso XI and his son Enrique II of Trastamara
Inside there is a magnificent Romanesque cloister from the 12th century and a Gothic cloister from the time of King Ferdinand III the Saint, as well as the most important Museum of Medieval Fabrics in Spain.