The word Poblet comes from the Latin populetum, which means "poplar grove", since the area has always stood out for its abundant vegetation and poplar forests. This natural wealth led to its declaration in 1984 as a Natural Site of National Interest, covering 2100 hectares and 50 natural springs.

The monastery of Poblet was founded when the Count of Barcelona, Ramon Berenguer IV, donated the lands of Populetum to the French abbey of Fontfroide around 1150, at a time when Sancho I of Provence held the position of abbot in that community. Fontfroide, a subsidiary of Clairvaux and located near Narbonne, received these lands located in the Barbera Basin, in the municipality of Vimbodí, near Espluga de Francolí and with the Prades mountains as a backdrop. The environment offered the ideal conditions for the foundation of a Cistercian monastery: isolation, abundance of water and an extensive area suitable for agriculture.

With the establishment of this monastery, four large Cistercian abbeys were integrated: Clairvaux (in the Absinthe valley, France), the Grande Selva (in Languedoc), Fontfreda (near Narbonne) and Poblet. The first community was established under Abbot Guerau in 1153, and there are documents recording a donation from the Viscounts of Cardona in 1151. During the following centuries, kings and noble families made numerous donations, which have made it possible to follow the progress in the construction and finishing of spaces such as the cloister and the passages of the church. A will of 1184 indicates that the temple was still under construction, and another document of the same year mentions a royal donation to illuminate the altar of Santa Maria, indicating that at least the presbytery was already in operation.

In 1340, Peter the Ceremonious ordered the creation of a royal and noble pantheon, eventually housing up to 16 graves. The choice of this burial place was linked to important donations of land, men and economic resources, and private chapels were also built, such as those of Urgel and Argensola. The most prominent lineages of Catalonia - among them the Counts of Urgel, Cervera, Cardona, Puigvert and Boixadors - played an important role in the history of the monastery.

Since its foundation, Poblet was protected and sponsored by the kings, a relationship that continued after the union of the crowns of Aragon and Castile. In 1493, the Catholic Monarchs visited the monastery accompanied by the infant Don Juan and Juan and Fernando, Christianized sons of one of the last kings of Granada. This visit is remembered, in part, for the presence of the one hundred maidens who accompanied Queen Isabella, who stayed in one of the halls of the abbey palace and significantly altered the life of the place.

The humanist Hieronymus Münzer visited the monastery in 1494 and was impressed by its architecture, the richness of its decoration and the large monastic community. With the extinction of the Royal House of Aragon, Poblet began a period of decadence, although some abbots tried to modernize it during the Renaissance. Thus, Abbot Caixal hired the sculptor Damian Forment to make, between 1526 and 1531, a stone altarpiece for the main chapel, a large-scale work whose high cost led the monks to revolt against their abbot, who was finally sentenced to perpetual imprisonment for "dilapidation and lack of observance."