In 1912, Hibernia hosted trials in naval aviation with the temporary addition of a runway to her foredeck, and the first launch of an aircraft from a vessel underway was achieved from her in early May.

That year, the squadron went to the Mediterranean Sea during the First Balkan War as part of an international blockade of Montenegro.

The squadron was assigned to the Grand Fleet at the beginning of the First World War, and served on the Northern Patrol.

On returning to the United Kingdom she was again attached to the Grand Fleet before being transferred to Nore Command in May 1916, finishing the war as an accommodation ship.

The new ships, though based on the general Majestic type that had formed the basis of the preceding four battleship designs, marked the first significant change in the series.

The King Edward VII-class ships were powered by a pair of 4-cylinder triple-expansion engines that drove two screws, with steam provided by sixteen water-tube boilers.

On 14 July 1910 she was rammed by the barque Loch Trool just after the latter had collided with the battleship Britannia, but Hibernia suffered no noteworthy damage.

[6] In January 1912, aviation experiments began at Sheerness aboard the battleship Africa, during which the first British launch of an aeroplane – the Short Improved S.27 biplane "S.38" (or "RNAS No.

[8] Samson took off from Hibernia while the ship steamed at 10.5 knots (19.4 km/h; 12.1 mph) at the Royal Fleet Review in Weymouth Bay, England.

[6] Based on the experiments, the Royal Navy concluded that aircraft were useful aboard ship for spotting and other purposes, but that interference with the firing of guns caused by the runway built over the foredeck and the danger and impracticality of recovering seaplanes that alighted in the water in anything but calm weather more than offset the desirability of having aeroplanes aboard.

[6] Upon the outbreak of the First World War in August 1914, the 3rd Battle Squadron, at the time under the command of Vice Admiral Edward Bradford, was assigned to the Grand Fleet and based at Rosyth, where it was reinforced with the five Duncan-class battleships,[10][11] It was used to supplement the Grand Fleet's cruisers on the Northern Patrol, and Hibernia continued her service as Second Flagship of the squadron.

[12] On 6 August, the day after Britain declared war on Germany, elements of the Grand Fleet sortied to inspect the coast of Norway in search of a German naval base violating Norwegian neutrality.

Four hours later, they met the 1st and 4th Battle Squadrons, en route from Scapa Flow, though they failed to reach the German High Seas Fleet before the latter withdrew.

The Grand Fleet remained at sea until late on 17 December, at which point the 3rd Battle Squadron was ordered back to Rosyth.

[18] On 23 January, the 1st and 2nd Battlecruiser Squadrons sortied to ambush the German I Scouting Group in what resulted in the Battle of Dogger Bank the following day.

The 3rd Battle Squadron patrolled the area with the rest of the Grand Fleet over the night before being detached at 08:00 on 25 January to steam to Rosyth.

The fleet went to sea again on 29 May for a patrol south to the Dogger Bank before returning to port on 31 May, again without having located any German vessels.

The ships departed Scapa Flow on 6 November 1915; Albemarle suffered heavy damage in a storm on the first night of the voyage and had to return for repairs,[6] assisted by Hibernia and accompanied by Zealandia.

[6][22] Before the end of January, Russell relieved her as divisional flagship, and Hibernia returned to the United Kingdom, being reassigned to the Grand Fleet upon arrival at Devonport Dockyard on 5 February 1916.

[23] In October 1917, Hibernia left the 3rd Battle Squadron and paid off into the Nore Reserve at Chatham Dockyard, where she served as an overflow accommodation ship.

To meet this requirement, it was suggested that Hibernia be converted to radio control and undergo other modifications so that she could assume duty as a target ship, but ultimately the pre-dreadnought battleship HMS Agamemnon became available and was selected instead.

[25] In July 1919, Hibernia was placed on the disposal list at Chatham, and on 8 November 1921 she was sold for scrapping to Stanlee Shipbreaking Company of Dover.