From 1923 onwards, the Mediterranean fleet was the major naval force under British control. In the North Sea the elimination of the German navy in 1918–1919, by the surrender and scuttling of its ships, had cleared the sea of the most serious enemy; in the Far East there was apprehension at the growth of both Japan's and the United States’ naval power, though these two tended to cancel each other out, being mutually hostile; the naval base at Singapore formed the basis for British power in the Indian Ocean and the China Seas. These two regions, therefore, were not held, in naval terms, very strongly, and their reserve strength was the Mediterranean fleet. Positioned as it was, its ships could sail quickly into the Atlantic and British waters, or reinforce the Indian Ocean and the Far East. The Rock of Gibraltar and the Suez Canal were therefore seen even more than before as essential imperial maritime links, and Malta was the main naval base.

In order for the Mediterranean fleet to be of use in a crisis, it had to be large, well-trained, and fully equipped. It was put through constant exercises, in many parts of the sea, and kept up-to-date in equipment so far as possible. It received the reinforcement of aircraft carriers from the beginning; the original carrier, Argus, was already being used in the Russian and Turkish troubles in 1921–1923, and the fleet received as its commanders the most capable admirals. But as the political situation developed, especially after 1930, its clear maritime advantage of the 1920s gradually eroded.

This was the classic age of the Mediterranean fleet. Sailors and officers were professionals, the disciplinary regime was benign, sailors received regular leave, and were rotated into different ships and through regular educational and retraining programmes. There were annual visits by parts of the fleet to places all around the sea – Greece and Turkey were favourites, though France and Yugoslavia and Italy were included; the visits were social occasions as much as exercises, promoting good international relations, at least supposedly (but they were also exercises in intelligence gathering). The ships were polished and painted to impress, but exercised in evolutions, firing practice, and navigation as well. Plans were developed to cope with possible naval operations. For ten years or so after 1923 the fleet rode the Mediterranean unchallenged and with vast confidence.