|NATO rank code||OF-7|
|Next higher rank||Vice-admiral|
|Next lower rank||Commodore|
Rear admiral (RAdm) is a flag officer rank of the Royal Navy. It is immediately superior to commodore and is subordinate to vice admiral. It is a two-star rank and has a NATO ranking code of OF-7.
The equivalent rank in the British Army and Royal Marines is major-general; and in the Royal Air Force, it is air vice-marshal.
The rank originated in the 17th century, in the days of naval sailing squadrons when each naval squadron would be assigned an admiral as its head. The admiral would command from the centre vessel and direct the activities of the squadron.
The admiral would in turn be assisted by a vice admiral, who commanded the lead ships which would bear the brunt of a naval battle. In the rear of the naval squadron, a third admiral would command the remaining ships and, as this section of the squadron was considered to be in the least danger, the admiral in command of the rear would typically be the most junior of the squadron admirals. This has survived into the modern age, with the rank of rear admiral the most junior of the admiralty ranks of many navies.
Prior to 1864 the Royal Navy was divided into coloured squadrons which determined career path. The command flags flown by a rear-admiral changed a number of times during this period.
The Royal Navy rank of rear admiral should be distinguished from the office of Rear-Admiral of the United Kingdom, which is an Admiralty position usually held by a senior (and possibly retired) "full" admiral.
Main article: List of command flags of the Royal Navy