Like most major powers, Great Britain, had many orders from overseas countries for ships of all types, including capital ships. 1913 Britain obtained an order for a battlecruiser, fast battleship type from Spain. Twelve months later, war broke out. Work on the ship was suspended pending other priorities. Work was resumed in 1915, after the hull was purchased from Spain, with a moderate priority. With upgraded bridge and machinery, the ship was expected to complete in 1917. Problems with the supply of the machinery put back the completion date till 1918. The Vengeance was out of synch with the rest of the Royal Navy vessels. A lot of it was to do with the main armament of twelve 14". This was the same mark of 14" gun as on the HMS Canada, the only ship in the Royal Navy with those weapons till the Vengeance was completed. (Another 14" ship was completed later, see HMAS Australis) The Royal Navy's weapon of choice during this period was the Mk-1 15" in twin and triple turrets. The other problem with the Vengeance was its speed. At 26-27 knots, the Vengeance had the fast battleship speed but had a battlecruiser armour scheme. That was the penalty paid for having the heavy twelve gun armament. Once World War One finished, the Vengeance was always going to be excess to requirements.
The setting up of the Dominion Navies in 1920 allowed ships like the Vengeance to find continued 'Commonwealth' service. Australis gladly accepted the Vengeance, where it would join other 14" ships with the same type of gun.
One advance that the Vengeance had aboard was what was supposed to be a dual purpose secondary armament. Eleven 4.7" were fitted but these guns only had a 60 degree elevation. These were the same guns as put aboard the early A-I class destroyers and leaders. Future refits would cure the low angle of the supposed AA guns. In a 1930 refit the 4.7" were replaced with single 4" dual purpose guns with an 85 degree elevation.
During a protracted refit from 1936 to 1938, the ship was completely stripped, above and below decks to produce a modern warship. New bridge and other superstructure, new armoured deck, but most of all a modern secondary and tertiary dual purpose weapon system. Allied to the new weapons was upgraded directors and electronics to make the most of their firepower. Further electronic enhancements were added whenever the ship entered a refit port.
