Together with her sister ship, Barfleur, she supported Allied operations during the Boxer Rebellion of 1899–1901 and contributed landing parties to participate in the Battles of the Taku Forts and of Tientsin.

The engines were designed to produce a total of 9,000 indicated horsepower (6,700 kW) which was intended to allow the ships to make a speed of 17 knots (31 km/h; 20 mph) using natural draught.

The engines proved to be slightly more powerful than anticipated and Centurion reached 17.05 knots (31.6 km/h; 19.6 mph) from 9,703 ihp (7,236 kW) during her sea trials.

Using forced draught, she attained 18.51 knots (34.3 km/h; 21.3 mph) from 13,214 ihp (9,854 kW) although this often damaged the boilers and was officially discouraged.

[4] The four 32-calibre, breech-loading 10-inch Mk III guns of the main battery were mounted in two twin-gun, circular barbettes, one forward and one aft of the superstructure.

The remaining three-pounders in the fighting tops were repositioned to the superstructure and the barbette hoods and the foremast was replaced by a signal mast.

[16] During the Boxer Rebellion, she contributed men to Seymour's expedition that attempted and failed to relieve the besieged International Legations in Peking, capital of China, between 10 and 28 June 1900.

[17] In addition, the ship put landing parties ashore which joined other forces in storming the Taku forts on 16–17 June and in relieving the foreign legations at Tientsin on 13–14 July.

[15] While anchored at Wusong, China, near Shanghai, she parted her mooring cables during a storm on 17 April 1901 and drifted across the bows of the battleship HMS Glory.

Glory's bow punched a hole in Centurion's hull below the waterline, but the damage was not serious and was repaired at Hong Kong.

[18] Centurion, with Seymour aboard, arrived at Portsmouth on 19 August, where she was welcomed by the local Commander-in-Chief and thousands of people lining the beach and pier.

[21] The ship began a reconstruction at Portsmouth that month, including a partial rearmament, that lasted until on 3 November 1903 when she recommissioned for another period of service on the China Station.

In 1905, the United Kingdom and Japan renewed the Anglo-Japanese Alliance which reduced the need for a large Royal Navy presence on the China Station and all its battleships were withdrawn.

[23] In August 1902 an obelisk was erected in Victoria Park, Portsmouth, in memory of the officers and men of the Centurion who had died in China.