Even prior to World War 1, the British Royal Navy was working on an aircraft carrier concept. It took its HMS Hermes, a Highflyer-class cruiser, and modified it to support a pair of floatplane aircraft for trials. The results of these tests proved the idea viable and work began on a purpose-built seaplane carrier. To expedite the procurement process, it was decided to purchase a vessel already being built and this led to a hull being forged by Blyth Shipbuilding Company of Blyth, Northumberland. The vessel saw her keel laid down on November 7th, 1913 and its purchase by the Royal Navy was completed in May of 1914.
Work then began on modifying the ship to sufficiently launch and land seaplanes from. All of the forward obstructions of the existing vessel were relocated aft to provide an unfettered deck over the forecastle - this included the sole smoke funnel. Likewise, her internal machinery was relocated aft of amidships as was the bridge superstructure with a commanding view over the new deck. A hangar was built below to service the expected fleet of eight floatplane aircraft and a pair of cranes installed to reclaim water-born aircraft upon their return. Installed machinery included three boilers with one vertical triple-expansion steam engine driving a sole shaft through 3,000 horsepower. Maximum speed was 11 knots with a range out to 3,500 miles. The complete crew complement numbered 180 personnel and local defense would be handled through four QF 12-pounder 12 cwt naval guns.
The assassination of Archduke Franz Ferdinand in late June of 1914 spurred Europe to war. Declarations rang out in July and Britain was at war in August. Work continued on the new vessel, now at a hurried pace, and she was launched on September 5th, 1914. Sea trials then followed and the ship was commissioned on December 10th, 1914 as HMS Ark Royal - the world's first purpose built seaplane carrier.
With Britain at war, HMS Ark Royal was quickly put into active service at sea. It was found that her machinery would limit her tactical value in operations with the fast Grand Fleet so she was sent to the Mediterranean Theater, arriving there for January of 1915. From there, the vessel supported the Allies in the disastrous Gallipoli Campaign (April 1915 to January 1916) where her aircraft provided reconnaissance and close-support services. As the waters proved too dangerous for her to linger, Ark Royal was ordered away for her own protection.
En route to Salonika, Greece, her air arm undertook various reconnaissance sorties including flights over Smyrna during November 1916. Ground attacks were conducted against Bulgarian forces thereafter. In March of 1917, Ark Royal was sent near Moudros, Greece where she served as a landing and launching hub for Allied seaplanes which then led to her January 1918 encounter with the German battlecruiser Breslau and the Ottoman battlecruiser Yavuz Sultan Selim. Despite both having been crippled by naval mines, Ark Royal's air power did little to finish the pair off. At Syros in early April 1918, Ark Royal served seaplanes of the Royal Air Force (RAF) and sailed for Piraeus in October. On October 30th, 1918, she was present at Constantinople for the Ottoman surrender. After the war, she supported RAF aircraft in action during the Russian Civil War (1917-1922) but in November of 1920, she was set in reserve.
HMS Ark Royal was reactivated in 1922 in support of British and French forces during the "Chanak Crisis" in September and returned to home waters in 1923 and given reserve status once more. She was commissioned for service again in 1930 and served as a training platform until about 1939 but not before being renamed as HMS Pegasus in 1934.Her original name would now serve a new Royal Navy carrier.
At the outbreak of World War 2, HMS Pegasus continued in her given role and also supplied transport and recovery services as the war situation evolved. From December 1940 to July 1941, she aided as a convoy escort and her anti-aircraft armament was improved along with radar being installed. In time, she returned to her post as a trainer and served in this role until February 1944 before being relegated to a barracks ship until May of 1946.
With the war having been over since September 1945, HMS Pegasus' service was no longer in need. In October 1946, she was briefly taken in by a Panamanian company to serve as a freighter (the "Anita I"). While work on her conversion was still incomplete, lack of payments led to a stoppage in 1948. The ship was then claimed by a Dutch shipbreaker In June of 1949 only to see her change hands once more, this time to a British shipbreaker. She was unceremoniously scrapped in 1950 after faithful service through two World Wars.