Admiral John (Jacky) Fisher radically transformed the Royal Navy in terms of its people, doctrine, equipment and structures. Dr Richard Dunley explains how.

Few service chiefs have had such a profound effect on their service as Admiral of the Fleet, Baron Fisher of Kilverstone, Chief of the British Royal Navy in 1904-1910, and again in 1914-1915, before resigning in frustration over Churchill's Gallipoli campaign.

Joining a wooden-hulled, sail-powered Royal Navy at the age of 13, by the time he retired aged 74, his Service was operating steel-hulled, oil-powered and technologically advanced battleships, with submarine and aviation arms. He was at the forefront of many of these reforms, but his impact went beyond the technology, overseeing profound changes in naval strategy (working alongside Julian Corbett - Season 1, Episode 1), doctrine, force disposition, personnel and training. Like other great strategic leaders, he was adept at shaping the political environment, securing for the Royal Navy the lion's share of the defence budget. Yet his legacy is mixed - his Royal Navy was undoubtedly a stronger, more capable fighting force but, according to our guest, was institutionally damaged and divided, and took some time to recover.

Dr Richard Dunley is a senior lecturer in history and maritime strategy at the University of New South Wales, Canberra, where he teaches at the Australian Defence Force Academy. His research focuses on the relationship between navies and technology, with a particular emphasis on the Royal Navy in the early 20th century.