The 1860s were a brutal decade for naval architects. The Battle of Hampton Roads in 1862 had just made every wooden warship in the world obsolete overnight, and the Royal Navy was scrambling. Edward Reed, the Chief Constructor, took the unfinished Camelion-class sloop on her stocks and reimagined her as a central battery ironclad - a small fortress at sea. The remodelled hull got a plough-shaped ram bow, a semi-circular stern, and a 4.5-inch wrought iron belt backed by 19.5 inches of teak. She came in at 1,350 long tons displacement, 180 feet between perpendiculars, with a crew of 130. She was launched on 9 February 1864, commissioned in May, and completed in June. The cost to the Royal Treasury: £62,474.

Enterprise carried four guns when she sailed: two old smoothbore 100-pounder Somersets, and two of the Royal Navy's bright new 110-pounder Armstrong breech-loaders. Much was hoped for the Armstrongs. Almost nothing came of those hopes. Tests in September 1861 had already shown the 110-pounder was worse than the old 68-pounder smoothbore at penetrating armour, and during the Battles for Shimonoseki and the Bombardment of Kagoshima in 1863 to 1864, breeches kept exploding. The Navy quietly withdrew the guns. By her 1868 Malta refit, Enterprise was rearmed with four 7-inch rifled muzzle-loaders - a step backward in mechanism but forward in reliability. Her wooden gun carriages were notoriously difficult to traverse even on a calm day. Few captains, one observer noted, would risk casting them loose in heavy seas.

Once commissioned, Enterprise spent the bulk of her active career attached to the Mediterranean Fleet, Malta-based, showing the flag through the years when Britain was negotiating the Suez Canal and the long Eastern Question. She steamed at about ten knots on her 690-horsepower Ravenhill engine, with three barque-rigged masts and 18,250 square feet of sail to extend her range. Her funnel had been awkwardly placed in the middle of the battery for protection - an arrangement that immediately impaired the working of the guns, and was relocated forward by November 1864. She returned to England in 1871 and was paid off into 4th Class Reserve at Sheerness in August. She had not fought a battle. She had not earned a name. She was, in every sense, an experimental ship that the Navy outgrew before she got the chance to prove herself.

She sat in reserve for fourteen years before being sold for scrap in 1885 for £2,072 - roughly three percent of what she had cost to build. Even her final journey was unlucky. On 6 October 1889, under tow from Plymouth to Liverpool for breaking up, Enterprise was caught in a gale off the Anglesey coast. The towline parted. She was driven ashore at Aberffraw, on the western edge of the same island whose Menai Strait approaches she had once been theoretically designed to protect. The wreck broke up where it grounded. There is a particular Victorian irony in a coastal-defence ironclad ending her days as scrap on the very coast she was built to defend - sent there not by enemy guns but by weather and a snapped rope and the patient logic of the sea.