The Cathedral of the Old Cathedral of Lleida, is the most emblematic monument in the city, it was built in the Romanesque style, although its vaults are Gothic ribbed vaults. It stands on the hill known as Turó de Lleida that dominates the city and the Segriá region.

In Catalonia, the persistence of Romanesque art until the 13th century produced architectural structures such as the Cathedral of Lleida. Its late-Romanesque, or transitional style, has the Romanesque forms and the monumentality of the Gothic. Its façades and capitals generated an important Romanesque sculptural workshop known as the School of Lleida.

The magnificent cloister, with its viewing gallery over the city, was built between the 13th and 14th centuries.

The cathedral was completed in the 15th century with the construction of the bell tower and the door of the Apostles.

In 1707 and given its important strategic position, the Old Seo became a military barracks, no longer performing religious functions.

Although it has gone through times of great neglect, the transfer of religious services has allowed the original style to be preserved without later additions of other styles.

The Paleo-Christian and Visigothic cathedral was located in the same place, which was later used as a major mosque in times of the Muslim occupation and which had been built in 832.

Counts Ramón Berenguer IV of Barcelona and Ermengol VI of Urgel conquered the city of Lleida from the Saracens in the years 1149, and it was Bishop Guillem Pere de Ravidats, transferred from the diocese of Roda de Isábena, who consecrated the mosque as a Christian cathedral under the invocation of Santa María la Antigua, the canonical being governed by the rule of San Agustín.

Bishop Gombau de Camporrells, after making numerous purchases of land and houses adjacent to the temple, started a new cathedral to attend to the increase in population in those years.