Jackie Fisher

As First Sea Lord, Fisher implemented sweeping reforms of the Royal Navy. He scrapped obsolete ships, concentrated the fleet in home waters, improved training, and introduced new technologies like submarines and destroyers. These reforms modernized the Navy.

As First Sea Lord, Fisher oversaw the design and construction of HMS Dreadnought, a revolutionary battleship with an all-big-gun armament and steam turbine propulsion. This ship rendered all previous battleships obsolete and triggered a global naval arms race.

Fisher resigned as First Sea Lord in protest over the Dardanelles campaign, which he opposed. His resignation caused a political crisis and weakened the government of H.H. Asquith. He was replaced by Henry Jackson.