Admiral of the Fleet Sir Alexander Milne, 1st Baronet,, was a Royal Navy officer. As a captain on the North America and West Indies Station he was employed capturing slave-traders and carrying out fishery protection duties. He served as a Junior Naval Lord under both Liberal and Conservative administrations and was put in charge of organising British and French transports during the Crimean War. He became Commander-in-Chief, North America and West Indies Station and in this role he acted with diplomacy, especially in response to the Trent Affair on 8 November 1861 during the American Civil War, when USS San Jacinto, commanded by Union Captain Charles Wilkes, intercepted the British mail packet RMS Trent and removed, as contraband of war, two Confederate diplomats, James Mason and John Slidell. He became First Naval Lord in the third Derby–Disraeli ministry in July 1866 and in this role took advantage of the Government's focus on spending reduction to ask fundamental questions about naval strategy. He again became First Naval Lord in the first Gladstone ministry in November 1872, remaining in office under the second Disraeli ministry and identifying the critical need for trade protection at times of war and demanding new cruisers to protect British merchant shipping.

Admiral of the Fleet is a five-star naval officer rank and the highest rank of the Royal Navy, formally established in 1688. The five-star NATO rank code is OF-10, equivalent to a field marshal in the British Army or a Marshal of the Royal Air Force. Apart from honorary appointments, no new admirals of the fleet have been named since 1995, and no honorary appointments have been made since 2014.