The floating battery Duque de Tetuán was an ironclad warship, a low-freeboard vessel similar in design to a monitor, of the Spanish Navy, and was constructed during the Third Carlist War to provide coastal defense and fire support for troops ashore.

[2] Some of the armor plate used in the construction of Duque de Tetuán came from the earlier armoured frigate Tetuan,[3] which had burned under suspicious circumstances during the Cantonist rebellion at Cartagena.

[5] Despite the urgent need for such a vessel to provide fire support in the government's campaign against the Carlists, Duque de Tetuán was not completed in time to participate in the war.

[2] Considered a third-rate ship by the close of the 19th century, Duque de Tetuán was decommissioned and struck from the official strength of the Armada by 1897.

[7] However, in 1898, the outbreak of the Spanish–American War led to its being recommissioned, to once more defend Ferrol against attack, the ship being fitted with controls for the electric mines that had been laid to protect the base.