Mark II guns were originally developed to suit India's coastal defence requirements.

[3] These were built and employed specifically as naval guns and were mounted as secondary armament as a heavier alternative to 6-inch guns, on the following ships : Mark III guns were built by Elswick Ordnance to arm the battleship Constitución they were building for Chile.

Swiftsure was decommissioned in 1917 and her guns were used for coast defence in Britain, as siege guns on the Belgian coast near Nieuport for attacking German batteries, and on M15-class monitors.

Mark IV guns were made by Vickers for the battleship Libertad they were building for Chile.

Britain acquired them by default in 1903 when she bought Libertad together with Constitución.