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
Captain (Royal Navy) Captain (Royal Navy) Captain (Capt) is a senior officer rank of the Royal Navy. It ranks above commander and below commodore and has a NATO ranking code of OF-5. The rank is equivalent to a colonel in the British Army and Royal Marines, and to a group captain in the Royal Air Force. There are similarly named equivalent ranks in the navies of many other countries. In the Royal Navy, the officer in command of any warship of the rank of commander and below is informally referred to as "the captain" on board, even though holding a junior rank, but