H.M.S. Northumberland was one of a unique group of battleships, the only five-masters ever built. Laid down at Millwall in 1861 and finally completed in 1868, her main armament consisted of 48-68pdrs. and she could steam at 14 knots. Refitted and cut down to a three-masted barque in 1875, she remained at sea until 1890 after which she was laid up in reserve until 1898. Employed as a training ship for stokers, 1898-1909, she then became a coal hulk until sold in 1927 and taken to Dakar.
The 'Black Battlefleet' was a contemporary term applied to those mid-Victorian ironclads whose hulls were painted a sombre plain black.