She was built at Havana, Cuba, to a design by Irish naval architect Matthew Mullan (domiciled in Spain under the name Mateo Mullán), originally intended as a ship of 112 guns.

[Note 1] She was reputed to be the largest warship in the world, for which she was nicknamed El Escorial de los mares by the Spanish, until surpassed in sheer size by the new type French 120-gun ships such as Océan (1790) and Orient (1791).

The weight of the additional guns, so high above her waterline, made her poor sailing qualities even worse, leading to her other nickname El Ponderoso.

Santísima Trinidad became the flagship of the Spanish fleet, taking part in the Franco-Spanish operations in the English Channel in the late summer of that year.

[citation needed] In 1797, she was the flagship of Teniente General José de Córdoba y Ramos, the Spanish commander, at Battle of Cape St Vincent on 14 February 1797, where she was badly damaged and nearly captured by the British fleet.

She struck her colours, but the British failed to take possession and she was saved by the Infante don Pelayo (74) and Principe de Asturias (112).

Several days later, Santísima Trinidad was spotted, still damaged, making her way back to Spain, and engaged by the 32-gun frigate HMS Terpsichore under Captain Richard Bowen, but she escaped.

She lost her mast and eventually surrendered with 200 dead and a hundred wounded to the Neptune, a 98-gun second rate commanded by Captain Thomas Fremantle.

Interior construction details are exposed on one side of the vessel, and visitors are able to use a computer interface and touch screen to take a virtual tour of the ship in Spanish, English, and French.