The Santa Ana class was built for the Spanish fleet in the 1780s and 1790s as heavy ships of the line, the equivalent of Royal Navy first rate ships. The other ships of the class were the Santa Ana, Mejicano, Salvador del Mundo, Real Carlos, San Hermenegildo, Reina María Luisa and Príncipe de Asturias. Three of the class were captured or destroyed during the French Revolutionary Wars.
Conde de Regla was constructed at Havana, funded by Pedro Romero de Terreros, Count of Regla, after whom the ship was named.
Conde de Regla's sea-trials took place in 1787 under Juan de Lángara y Huarte, who reported that the ship sailed smoothly and the gun batteries operated efficiently.
In 1797, Conde de Regla was with the Spanish fleet which fought the British at the Battle of Cape St. Vincent. The Spanish fleet was defeated and four ships were lost, although Conde de Regla survived the battle with losses of 9 killed, including Commodore Count Amblimont and 16 seriously wounded, including Comandante Jerónimo Bravo.
Between 1799 and 1801, Conde de Regla was with the combined French and Spanish fleet stationed at Brest after participating in the Croisière de Bruix campaign.During the Napoleonic Wars Conde de Regla was laid up at Arsenal de la Carraca.
In mid-1810 Conde de Regla, in poor repair and with the Spanish Navy lacking the materials to repair her, was broken up at Port Mahon. Her timbers were used as firewood by the local population.