It has been in ruins since 1939, when it was destroyed when Cartagena was shelled in the Spanish Civil War by Nationalist forces.

In 1243 Alfonso X of Castile launched a campaign to reconquer the Kingdom of Murcia, and petitioned Pope Innocent IV to restore the Diocese of Cartagena.

The first bishop of the new phase of the Diocese was the Franciscan friar Pedro Gallego, Alfonso's confessor.

In medieval and Renaissance documents the church is described as "Iglesia Mayor", and is only called "Old Cathedral" from the eighteenth century.

The church was restored by the architect Victor Beltrí, in Romanesque style with modernist elements.