The ship was ordered by the Chilean Navy, but she was purchased by the United Kingdom as part of ending the Argentine–Chilean naval arms race.

After the beginning of World War I in August 1914, Swiftsure escorted troop convoys in the Indian Ocean until she was transferred to the Suez Canal Patrol in December.

Swiftsure was assigned to convoy escort duties in the Atlantic from early 1916 until she was paid off in April 1917 to provide crews for anti-submarine vessels.

Swiftsure was ordered by Chile, with the name of Constitución, in response to the Argentine purchase of two armoured cruisers from Italy during a time of heightened tensions with Argentina.

The ship was designed to Chilean specifications, particularly the requirement to fit in the graving dock at Talcahuano, and was regarded by the British as a second-class battleship.

[2] The ship was powered by two four-cylinder inverted vertical triple-expansion steam engines, each driving one propeller.

A dozen Yarrow water-tube boilers provided steam to the engines which produced a total of 12,500 indicated horsepower (9,300 kW) which was intended to allow them to reach a speed of 19.5 knots (36.1 km/h; 22.4 mph).

[5] She carried a maximum of 2,048 long tons (2,081 t) of coal, enough to steam 6,210 nautical miles (11,500 km; 7,150 mi) at 10 knots (19 km/h; 12 mph).

[2] In service she and her sister proved to be more economical than first thought with an estimated range of 12,000 nautical miles (22,000 km; 14,000 mi) at 10 knots.

[8] A major problem with the guns on the main deck was that they were mounted low in the ship—only about 10 feet (3 m) above water at deep load—and were unusable at high speed or in heavy weather as they dipped their muzzles in the sea when rolling more than 14°.

The waterline main belt was composed of Krupp cemented armour (KCA) 7 inches (178 mm) thick.

[13] Swiftsure was ordered by Chile as Constitución and laid down by Armstrong Whitworth at Elswick on 26 February 1902 and launched on 12 January 1903.

She collided with her sister ship Triumph on 3 June 1905 and suffered damage to her propellers, sternwalk and aft hull.

Swiftsure was briefly placed in reserve at Portsmouth Dockyard from 7 October 1908 until 6 April 1909 when she was recommissioned for service with the Mediterranean Fleet.

From 27 January to 4 February 1915, the ship helped to defend the Canal near Kantara during the First Suez Offensive by Ottoman forces.

In the autumn of 1918 she was disarmed and stripped for use as a blockship in a proposed second attempt to block the entrance to the harbor at Ostend, but the war ended before this operation could take place.