The need for a more mobile strike capacity led to the development of the aircraft carrier - the backbone of modern naval aviation. was the first purpose-built seaplane carrier and was also arguably the first modern aircraft carrier. She was originally laid down as a merchant ship, but was converted on the building stocks to be a hybrid airplane/seaplane carrier with a launch platform and the capacity to hold up to four wheeled aircraft. Launched on 5 September 1914, she served in the Dardanelles campaign and throughout World War I.