ARA Almirante Brown was a central battery ironclad of the Argentine Navy built in the 1880s by Samuda Brothers in London.

In the 1860s, the Argentine Navy had few warships, but the government of President Domingo Faustino Sarmiento embarked on a modest program to strengthen the fleet.

By the end of the decade, the naval ascendancy of their rival in Chile (in part due to their successes in the War of the Pacific against Peru and Bolivia that would begin in 1879), prompted the Argentine government to purchase another, larger and more powerful vessel that would be able to overpower any Chilean counterpart.

[1][2] The acquisition of Almirante Brown led to a minor arms race; she prompted the Brazilian Navy to purchase a pair of larger ironclads, Riachuelo and Aquidabã.

[4] Her hull was steel-built, with a 3 in (76 mm) thick layer of teak, covered with zinc sheathing to protect it from biofouling during lengthy periods between dry-docking for cleaning; accumulations of marine growth would reduce the ship's speed.

[9] To supplement her steam engines on longer voyages, Almirante Brown was fitted with a sailing rig for auxiliary cruising.

[8] Almirante Brown was equipped with a main battery of eight 8-inch (203 mm) BLR Armstrong guns, all mounted individually in casemates.

[4] These breech-loading guns were a new development, which rendered Almirante Brown a significantly more powerful vessel than even those that had been completed a few years earlier.

Above the waterline, the belt was 9 in (229 mm) thick amidships in the central citadel, where it protected the propulsion machinery spaces and ammunition magazines.

On either ends of the citadel, a curved armor deck that ranged in thickness from 1.25 to 1.5 in (32 to 38 mm) provided a degree of protection against enemy fire.

[4][13] In 1878, Argentina made inquiries in Britain to buy a new, ocean-going capital ship for its navy, which to that point, had consisted of only coastal and riverine forces, centered on the two small El Plata-class monitors.

[11] Upon her delivery to Argentina, she was the largest vessel in the Argentine fleet, and remained so until the four Garibaldi-class armored cruisers were acquired in the late 1890s.

[20] In the following year, Almirante Brown, along with most of the heavy units in the Argentine Navy, took part in putting down the naval defections in the revolution of 1893,[21] where the ironclad shelled and disabled the rebel torpedo boat Murature off Martin García island.

[23] On 15 October 1904, Almirante Brown hosted the Argentine naval minister, Juan A. Martín [es], and a delegation of foreign naval officers, including Rear Admiral French Ensor Chadwick of the US Navy; Martin welcomed them on behalf of the new government under President Manuel Quintana, who had recently taken office.

[24] By the 1920s, Almirante Brown had been reduced to a coastal defense and training ship, having long since been rendered obsolete by the dreadnought battleships Moreno and Rivadavia.

[25] On 17 December 1921, crewmen from Almirante Brown rowed ashore to defeat a group of about 250 brigands based in Mata Tapera.