Commodore (Royal Navy) Commodore (Royal Navy) Commodore (Cdre) is a rank of the Royal Navy above captain and below rear admiral. It has a NATO ranking code of OF-6. The rank is equivalent to brigadier in the British Army and Royal Marines and to air commodore in the Royal Air Force. The rank of commodore was introduced during the 17th century in November 1674 (though not legally established until 1806). In 1684 the navy introduced two classes of commodore, the first known as a "Commodore Distinction" and the other a "Commodore Ordinary"; these would later evolve into commodores first and second class. In
History of the Royal Navy vessels being two s and fifteen s and heavy cruisers. The London Naval Treaty of 1930 deferred new capital ship construction until 1937 and reiterated construction limits on cruisers, destroyers and submarines. As international tensions increased in the mid-1930s the Second London Naval Treaty of 1935 failed to halt the development of a naval arms race and by 1938 treaty limits were effectively ignored. The Navy made a show of force against Mussolini's war in Abyssinia, and operated in China to evacuate British citizens from cities under Japanese attack. The re-armament of the Royal Navy was well under way by