Admiral of the Fleet Sir William Henry May was a Royal Navy Officer. As a junior officer he took part an expedition to rescue Commander Albert Markham who had got into difficulty trying to reach the North Pole via Smith Sound, the sea passage between Greenland and Canada's northernmost island, Ellesmere Island.

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.