The white, blue and red ensigns
Naval ensigns are the three flags that mark which ship of the Royal Navy flies them and why: the white ensign flies over warships and other commissioned vessels, the blue ensign is the civil flag of merchant and registered vessels, and the red ensign, the red flag of the Royal Naval Reserve, is flown by reserve ships and, on shore, by British merchant ships in foreign waters. The system is a 3 part one, each part distinguished by a 15 by 10 foot fly of white, blue or red bearing the Union Flag in the canton, and every destroyer of the fleet has flown the same white ensign for more than a century. Where the ensigns sit among the rest of the service colours, and what each one signals, are the two questions this page answers, with the destroyer classes of the Fleet as the standing example.
The ensigns are the working flags of the service and are the third family after the national flag and the jack in the set of Flags of the Royal Navy. The white ensign belongs to the Fleet, the blue ensign to the merchant registry, and the red ensign to the reserve, and each has its own rule about who may fly it and where. The naval jack is a companion flag that flies from the jackstaff at the bow while the ensign flies from the jackstay at the stern, and a warship at sea carries the two at once, one forward and one aft. Name memorabilia of Royal Navy destroyers, from model ensigns to the pennant flags carried in the wardrooms of the flotillas, keeps the association between a class and its colours on record long after the last ship is broken up. The classes that have carried the white ensign, from the 4 knot D class of 1904 through the 31 knot Type 45 destroyers, form the Royal Navy destroyer classes that give the Fleet its most numerous and best known line of ships.
What the white ensign is and who flies it
The white ensign is the flag of the Royal Navy, and it is the ensign of the 79 commissioned warships of the Fleet today, including the 6 Type 45 destroyers that carry it from the jackstay at the stern. It flies from the jackstay, not from the masthead, and the masthead carries the commissioning pennant of the commanding officer, a long tapering flag whose length marks rank. The white field with the Union Flag in the canton is the oldest of the three, and its use as the Fleet ensign goes back to the 1707 Act of Union, when the white ensign of the old Scottish service was set aside for the combined Navy. A ship flying the white ensign is a warship, and the moment she loses it she is no longer in commission in the eyes of the flag.
What the blue ensign is and who flies it
The blue ensign is the civil ensign of the United Kingdom, and it is flown by British merchant ships, fishing vessels and registered craft, the majority of which are the more than 1,000 vessels that fly it in the home waters of the Fleet. It is the same white canton on a blue field, with the difference that the fly bears the badge of the department that employs it, such as the Royal Navy badge, the Admiralty coat of arms or the emblem of the Coastguard. When a merchant vessel is pressed into service as an armed auxiliary, or is under the direct command of a naval officer, the blue ensign yields to the white, and the same ship changes her flag the moment the naval order ends. The blue ensign is therefore the flag of the registry and the white ensign the flag of the command, and a ship that has served under both carries the memory of each in her records.
What the red ensign is and who flies it
The red ensign is the flag of the Royal Naval Reserve, and it is flown by reserve ships and, on shore, by British merchant vessels in foreign waters, the red flag of the reserve being the oldest of the three in its present form. It is the same Union Flag in the canton on a red field, and its history is bound up with the East India Company, which flew red before the 1707 Act of Union set the colour aside for the Navy. The red ensign is the ensign that the destroyer classes of the Fleet met most often in foreign ports, for it was the flag of the merchantmen that the destroyers escorted, and the association between the two flags is the reason the reserve and the Fleet share so many customs. The 14 Royal Naval Reserve divisions that fly the red ensign on shore keep the link between the reserve and the Fleet alive in every port.
Where the destroyer classes sit in the system
The destroyer classes are the Fleet's standing line of ships, and every class from the D class of 1904 to the Type 45 has flown the white ensign from commissioning day to decommissioning day. The 31 knot Type 45 destroyers of the current Fleet, the 6 ships of the class led by HMS Diamond, carry the ensign in the same form that the 28 knot D class carried in 1904, and the continuity of the flag is what makes the line of the classes a line of one service rather than a string of separate builds. The table below sets the three ensigns against the class that best represents each in the modern Fleet.
| Ensign | Field | Fly by | Standing example |
|---|---|---|---|
| White ensign | White | Commissioned warships | Type 45 destroyers, 6 ships |
| Blue ensign | Blue | Registered merchant vessels | Escorted merchantmen of the convoys |
| Red ensign | Red | Royal Naval Reserve ships | Reserve divisions in foreign ports |
The destroyer classes sit at the centre of the system because they are the ships that have moved between all three fields, and a ship that has served under the white and been escorted by the red carries the whole of the ensign system in her service record. The 52 destroyer classes that the Fleet has built since 1904 are the measure of how long the white ensign has carried the line, and the 6 ships of the Type 45 are the current count of the ships that fly it in the destroyer line.
How the jack and the ensign work together
The jack and the ensign work as a pair, and the jack flies from the jackstaff at the bow while the ensign flies from the jackstay at the stern, the two flags of a warship at sea being the jack forward and the ensign aft. The jack of the Royal Navy is the same Union Flag on a white field, and it is the jack that the destroyer classes carry at the bow in the same form that the D class carried in 1904. A ship that flies the jack at the bow and the ensign at the stern is in commission, and the moment either flag comes down the ship is no longer a warship in the eyes of the flag. The 2 flags of a warship are the jack and the ensign, and the 1 commissioning pennant at the masthead marks the rank of the officer who commands her.
Why the colours are white, blue and red
The colours are white, blue and red because the 1707 Act of Union set each colour to a branch of the combined service, and the 3 colours of the ensign system are the direct legacy of that single act. White went to the Fleet, blue went to the merchant registry and red went to the reserve, and the assignment has not changed in more than 300 years. The 3 fields are the same in every other respect, each bearing the Union Flag in the canton, and the only difference between the three ensigns is the colour of the fly. The 15 by 10 foot proportion is the standard size for the ensign of a destroyer, and the same proportion is used for the jack and for the commissioning pennant of the Fleet. The 3 colours are the answer to the question of what the white, blue and red ensigns are, and the 1707 Act of Union is the source of the assignment that has made the three a fixed system since the combined Navy first flew them.