- Design and Symbolism
- Official Use
- Legal Status
- Appropriate Display, Storage and Disposal
- Sub National flags of the UK
- Diplomatic flags & Representative of the sovereign
- National flag at sea
- National flag at airports and military installations
- What about Wales?!
Design & SymbolismThe Union Jack symbolises the unity of the United Kingdom. This is achieved by the combination of three crosses representing the patron saints of the British constituent countries. Notably the Crosses of St George, St Andrew and St Patrick:
Terminology (Union Flag or Union Jack?)The British flag is popularly known as the Union Jack. It is often though that the flag is "officially called the Union Flag and should only be called the Union Jack at sea." That statement is derived from the belief that the flag became known as the Union Jack due to it's use as the United Kingdom's naval jack (which in itself means that statement is incorrect as jacks are only flown when the vessel is alongside rather than at sea). However a recent Flag Institute (FI) study has cast doubt on this common belief.
When the flag was first introduced in 1606 it was simply known as the "British flag," it is not until 1625 that the word "Union" first appears in reference to the flag. There are various theories about how it became known as the "Union Jack." One is that Jack is derived from James, as in King James I/VI who introduced the flag.
Commander Bruce Nicolls OBE RN(Rtd) wrote an article about the terminology on the FI website exploring the history of the name "Union Jack."
A jack is a secondary flag flown from a Jackstaff at the bow of a ship, generally only when alongside in harbour, which was not introduced until the 18th Century. However as Cdr Nicolls points out the term jack historically refers to the size of the flag rather than where on the vessel it was flown. In deed he points out that the Admiralty (who were one of the top authorities in regards to flags) called the flag the Union Jack no matter what role the flag was being used. In 1902 the Admiralty went a step further and said both terms (Union Flag and Union Jack) could be used officially. In 1908 Parliament even stated "the Union Jack should be regarded as the national flag."
To read Cdr Nicoll's article please click HERE.
In Canada the Union Jack is officially known as the "Royal Union Flag."
BBC guidelines state that both Union Flag and Union Jack are acceptable to use, and you may notice I use both terms. In conclusion to terminology both names (in the UK at least) are official regardless of what role the flag is in.
OriginsIn 1603 Queen Elizabeth I of England died childless, brining the Tudor dynasty to an end. The closest relative to Elizabeth was the son of her cousin, Queen Mary I of Scots (who Elizabeth had executed) King James VI of Scotland. This is an event known as the Union of the Crowns, while England and Scotland would remain separate countries for another century, the fact that both countries shared a monarch ment that they seldom did anything without the other. This lead to King James I/VI issuing this extraordinary decree in 1606 fallowing altercations between English and Scottish ships over flags:
"A Proclamation declaring what Flags South and North Britains shall bear at Sea
"Whereas some difference has arisen between our Subjects of South (England) and North Britain (Scotland), Travelling by Sea, about the bearing of their flags, for avoiding of all such contentions hereafter, We have with the advice of our Council ordered That from henceforth all our subjects of the Isle and Kingdom of Great Britain and the Members thereof shall bear in their maintop (main mast) the Red Cross, commonly called St George’s Cross, and the White Cross, commonly called St Andrew’s Cross, joined together, according to a form made by our Heralds and sent by Us to our Admiral to be published to our said Subjects. And in their foretop (Fore mast) Our Subjects of South Britain shall wear the Red Cross only as they were wont, and our Subjects of North Britain in their Foretop the White Cross only as they were accustomed. Wherefore We will and command all our Subjects to be conformable and obedient to this Our Order, and that from henceforth they do not use to bear their flags in any other Sort, as they will answer the contrary at their Peril.
"Given at our Palace of Westminster the 12th. day of April in the 4th. year of our Reign of Great Britain France and Ireland Anno Domini 1606."
This proclamation does not state the exact form of the flag, only that it contain both the crosses of St George and St Andrew. There were various (hideous) unsuccessful candidates, another proposal was for quartering like the Royal Standard:
The final design adopted was what we would recognise today as a Union Jack. St Andrew's Cross going under that of Saint George (although not always in line!).
There is often speculation about the exact shade of blue, as none where originally specified, and more than likely different shades were used by different flag makers. It also appears that at some point probably after the 1707 act of union that the Admiralty darkened the 'sky blue' of the field of St Andrew's Cross to a darker 'navy blue.' Presumably so the blue wouldn't fade so quickly allowing the flag to last longer (and thus saving money).
It should be noted the Union Flag at this point was in no way a national flag of either Scotland or England, but rather a secondary flag for use at sea designed to be used alongside the relevant English and Scottish national flag, it was later restricted to warships:
Needless to say that the accepted design was not popular with the British to begin with. The English disliked how their white field on St George's cross was replaced by Scotland's blue, and the Scots strongly disliked how St George's Cross was on top of St Andrew's Cross. Patriotic Scots flew their own version with St Andrew's Cross placed proudly on top:
The Scottish Parliament petitioned the King to accept this redesign (after all he was a Scot himself) but he declined. Imagine what the Union Flag would look like today if this was the accepted design?! The Scottish variant does however seem to have had some form of unofficial approval from some of the local authorities (or they turned a blind eye to it). A 1675 drawing of Edinburgh Castle by John Slezer shows the castle flying what at first appears to be a St Andrew's Cross, however closer inspection reveals it to be a Scottish Union Jack like the one above:
Fallowing the victory of Parliament and the execution of King Charles I in the English Civil War/War of the Three Kingdoms, the British nations experimented briefly with republicanism. This period known as the Interregnum in the British Isles saw the Union Jack all but disappear.
Even the Royal Navy during the civil war didn't use the Union Jack. The Royalist Jack of 1643 was:
To begin with the Republic didn't exercise authority over Scotland, but even when this was achieved the Union Jack wasn't used, possibly because Royalist ships loyal to the Royal Family in exile continued to use it. The Flag used by the Admiral, Rear Admiral and Vice Admiral at sea between 1649 - 53 was:
It was not until 1651 Scotland was added (and Ireland dropped) to the Commonwealth flag although the above flag still seems to have been used. This flag was quartered:
The last flag of this period is known as the Protectorate Jack which replaced the cross and harp flag. It was a Union Jack but defaced with an Irish harp. This was used until the restoration of the monarchy in 1660:
Acts of Union (Great Britain & the United Kingdom)Fallowing the Act of Union of 1707 uniting England(including Wales) and Scotland into the new Kingdom of Great Britain, a flag was needed for this new state. The Union Flag was the obvious choice. However the Scots once again pushed for a new variant with the Cross of St Andrew over that of St George. There were two Scottish proposals, including the one mentioned earlier and the one below:
Following the Act of Union 1801 When the kingdoms of Ireland (Ireland was always until this point technically a separate kingdom) and Great Britain were united to form the United Kingdom of Great Britain & Ireland, the flag got its final touch to make the modern flag still in use today. The Cross of St Patrick was added. However it was counter changed rather than symmetrical introducing the need to display the flag the right way up!
Thus the evolution of the Union Jack looks like this:
Ratios and ProportionsThe most common and accepted ratio today is 1:2. However other ratios have been used in the past. The Royal Navy's book "Flags of all Nations" states both the 1;2 and 3:5 ratios are official. In the latter case the diagonals of the St Patrick's cross are not quadrilaterals and are cut off as shown:
By Her Majesty's GovernmentUntil July 2007 the Union Flag was only flown on Government Buildings (Building owned or occupied by The Crown aka state, civil servants, not local authorities, armed forces or private citizens) on days designated by the Department for Culture, Media and Sport (DCMS). On 5th July the then Prime Minister Gordon Brown announced that the Union Flag would fly every day of the year from 10 Downing Street. Other Government Departments were asked to follow and all government building in Whitehall followed.
Before this the Union Flag was only flown from the palace of Westminster (aka Houses of Parliament) when Parliament was in session. However it now flies daily.
In the devolved governments of Scotland and Wales the regional flag is the primary flag on the Non designated days, meaning that if there is only one flag pole the regional flag will fly on all days except the days specified by DCMS when it is replaced with the Union Flag.
In Northern Ireland the Union Flag is only flown from buildings of the NI Office, NI Assembly & Executive buildings and court houses on designated days (with the exception of the Duchess of Cornwall's Birthday). No other flag has any legal status in Northern Ireland.
All UK Police forces fly their relevant police flag except on the designated days when the Union Flag is used. The exception is the Police Service of Northern Ireland who can only use their police flag and no other flag regardless of day, for political reasons.
Since the beginning of 2013, the designated days have been:
- 9 January: birthday of The Duchess of Cambridge
- 20 January: birthday of The Countess of Wessex
- 6 February: anniversary of The Queen's accession in 1952
- 19 February: birthday of The Duke of York
- Second Sunday in March: Commonwealth Day
- 10 March: birthday of The Earl of Wessex
- 21 April: The Queen's birthday
- 9 May: Europe Day
- 2 June: anniversary of The Queen's 1953 coronation
- 10 June: birthday of Prince Philip, Duke of Edinburgh
- A Saturday in June: The Queen's Official Birthday
- 21 June: birthday of The Duke of Cambridge
- 17 July (N.Ireland excluded): birthday of The Duchess of Cornwall
- 15 August: birthday of The Princess Royal
- Second Sunday in November: Remembrance Sunday
- 14 November: birthday of The Prince of Wales
- 20 November: anniversary of the wedding of The Queen and The Duke of Edinburgh
- Wales – 1 March: Saint David's Day
- Northern Ireland – 17 March: Saint Patrick's Day
- England – 23 April: Saint George's Day
- Scotland – 30 November: Saint Andrew's Day (St Andrews day is unique as the saltire is allowed to replace the Union Jack if only one flag pole is available).
- Greater London: The day of the opening or proroguing of Parliament
Other building of StateIn addition to state buildings, the Union Jack is flown over Royal residences in England (including but not limited to Windsor Castle, Buckingham Palace and St James' Palace) when a member of the Royal Family is not in residence. This is because when a Royal is in residence the relevant Royal Standard is used. Previously the flag pole was kept bear when a Royal was not in residence, but fallowing the death Diana Princess of Wales in 1997 the public observed no flag was flying at half mast over Buckingham Palace (the Royal family were in Scotland at the time), The Queen ordered a break in protocol in that the Union Flag fly at half mast until the day of the funeral. From then on the Union Flag was used anytime the Royal Standard was not flying (when the Queen is not in residence) The Union Flag has been flown at half mast from the palace on days of national mourning including the death of members of the Royal Family, New York 9/11, London July 7 and Paris 2015 Terrorist attacks, death of former US President Gerald Ford and former Prime Minister Baroness Margret Thatcher.
The Union Flag is also flown daily from the main flag poles of the Tower of London and Edinburgh Castle.
Royal residences in Scotland do not use the Union Flag when a member of the Royal Family is not in residence using instead the Royal Banner of Scotland.
By Private Citizens
Civilians in general are not authorized to display any flag except a banner of their coat of arms (if they have one). However it is recognised that the use of the Union Jack and other flags on land by private citizens is practised and has been for a long time. The view of the state is that it does not force the public to use any flag and is relatively relaxed on the use of flags of whatever description by the public (with the exception of the Royal Standard and diplomatic flags).
Outside the United Kingdom
Crown Dependencies and Overseas Territories
The national flag of the United Kingdom is the flag of all dependences and overseas territories. However all Crown Dependencies have their own unique flag that may or may not be used by the local administration. Most UK Overseas Territories also have a their own flag used by the local administration, this is mostly (but not always) the relevant state ensign with the Union Flag in the canton used on land.
Canada & Other Commonwealth nations
The Royal Union Flag of Canada is used as the state flag of Canada and flown from state buildings on designated days. This is also practiced by Canadian Navy vessels in home waters, who fly it from their mast of special days. This is due in part as a compromise to conservative groups when the national flag was changed in 1965. Some other countries use it on a semi-official/unofficial basis.
Legal StatusThere is no law or Act of Parliament making the Union Flag the national flag of the United Kingdom. It has become the national flag through precedent rather than law. However various statements from the government at various points show that as far as it is concerned it is the national emblem. It is first mentioned as the national emblem in Parliament in 1901 when it was stated "The Union Jack should be regarded as the national flag." In 1933 the then Home Secretary stated "The Union Flag is the national flag and may properly be flown by any British subject on land."
In Scotland the Court of the Lord Lion (which has legal jurisdiction for heraldic affairs in Scotland) confirms the Union Flag "is the correct flag for all citizens and corporate bodies of the United Kingdom to fly to demonstrate their loyalty and their nationality."
In 2008 a "Union Flag" Bill was introduced as a bill in parliament by Andrew Rosindell MP. This bill sought to legally confirm the Union Flag as the national flag, thus removing any potential legal implications or disputes in regard to its use. It would also confirm the name as both Union Flag and Union Jack. Unfortunately this Bill did not become an Act of Parliament (meaning it did not become law). A copy of the Union Flag Bill 2008 can be seen here on the FI website
Appropriate Display, Storage and DisposalSome pointers about using the flag and how it should not be used. Unfortunately a lot of people don't seem to know what the inappropriate ways to use the flag are, leading to something like the situation below. Here is a rather comical example in one picture of how it shouldn't be used:
Number one it is being used on a yacht, and under no circumstances should the Union Flag be used on a private vessel, there are other flags that should be used, that are covered further down. Number two is that it is UPSIDEDOWN! The flag next to it seems appropriate for the circumstances lol.
Fly it the right way Up?Because the red diagonals of the Cross of St Patrick are counter-changed rather than symmetrical on the Union Flag it is possible to fly the flag upside-down. Traditionally an upside down flag is a signal of distress or even an insult, hence why it is important to know how to display the flag right. Basically the red diagonals towards the hoist (end at the flag pole) are closer to the blue at the bottom leaving a large white gap between them and the blue above them. The opposite is the case at the fly end.
There are numerous examples of the flag being used the wrong way. But here are a few more high profile cases. When the Prime Minister David Cameron first visited the USA he was greeted by an honour guard with a UK flag. However there was a potential diplomatic incident when official's noticed before the PM's plane landed the flag was upside-down!
Fortunately this problem was corrected before the Prime Minister landed. While it is sometimes excusable and understandable for foreigners to get it wrong the same cannot be said of Britons! It is hard (and embarrassing) to highlight the mistakes of foreigners for misuse of the flag when even your own countrymen don't know any better! Here are just two examples of the pride of British sport getting it wrong!
All the pride, hard work and effort of winning a medal destroyed in one embarrassing and easily avoidable swoop. One reason why people should be made more aware of their own flag.
Folding and Storing the flagThere are a number of ways to fold the flag. The main way is like the Americans to fold it into a triangular shape. This is done at funerals and events like ceremonial sunsets. The Royal Navy method of folding the flag is:
The Union Flag is pulled taut and folded in half, lengthways (Fig. 1).
Keeping the Union Flag taught it is then folded in half (lengthways) a second time (Fig. 2).
A straight fold of 1/14 of the flag’s length (20cm on a casket cover) is taken from the foot of the Union Flag (Fig. 3). This fold may not be necessary, or may need to be a different length, depending upon the shape, size and material of the flag being folded – practise first!
The first triangular fold is made ensuring it is within 5mm of the straight edge (Fig. 4).
The triangular folding procedure continues until it reaches the head of the Union Flag (Figs. 5, 6 & 7).
Any remainder is tucked away into the fold of the triangular shape (Fig. 8 & 9).
The Union Flag ready for presentation (Fig. 10).
A British tradition in flags is folding the flag so that it will run up the pole folded, then by pulling a cord, unfurl at the top of the pole. This is known as breaking the flag and is usually done to signal the arrival of a VIP. It is frequently done with the Royal Standard. this is done by
1. Fold in half
2. Fold in half again
3. Fold the last 1/3 inwards
4. Roll towards the heading
5. Tie with light cotton
6. The flag is now ready for breaking
2. Fold in half again
3. Fold the last 1/3 inwards
4. Roll towards the heading
5. Tie with light cotton
6. The flag is now ready for breaking
See Video clip:
After folded it should be stored out of direct sun light. Otherwise you might find the colours of the visible section noticeably more faded than the rest of the flag!
Disposal of the FlagIf the flag is no longer suitable for use, due to the colours fading or becoming torn or tattered through use, then it must be disposed of in a dignified way. There is no specific way to dispose of it but accepted dignified ways include cutting the flag into strips that no longer resemble a flag, or to burn it in a dignified way. An undignified way to dispose of the flag is as I once seen in a County Londonderry village is to put it into a waste bin in the street for all to see!
For more on protocol in use of the National Flag see the FI guidelines
British Sub-National FlagsIn recent years regional identity as well as national identity has seen an increase in the UK. While some areas of the United Kingdom always had a strong independent identity recently more and more people want to display that. So regional flags are now as popular (and in some cases more popular) than the Union Flag itself, and are used as a local alternative to the national flag.
Constituent Countries of the United KingdomEngland
The flag of England dates back to the early Crusades. the dragon slaying St George was a popular figure among English Crusaders, who brought this cult back home, and changed the official patron saint of England to St George from Edward the Confessor. St George's Cross has no legal status, but is used by the Church of England and English Sport teams, as well as Private citizens and local authorities. It is also a central emblem in the Union Jack.
The flag of Scotland known as St Andrew's Cross is one of the oldest flags in British history. According to Legend the Christian Apostil St Andrew was crucified on an X shaped cross. The legend of the origins of the flag is from a 9th Century battle where the Scots were fighting the Picts. The story goes that a strange white X shape appeared in the sky above the Scottish troops, who taking it as a sign fro St Andrew were inspired on to victory. The white X on sky blue field is derived from this legend. The flag of Scotland is used by the Scottish regional government, local authorities and private citizens, as well as being a main component in the Union Jack.
standard of Henry VII, who is said to have used a standard bearing a red dragon on the Tudor colours of green and white at the battle of Bosworth Field in 1485. In 1807 a design based on this became the Royal Badge of Wales, a motto was added in 1953. The current flag is derived from this badge. In 1959 the Government started using this flag. The Welsh flag is used by Welsh sports teams, regional government, local authorities and private citizens.
coat of arms of the Northern Ireland Parliament. This flag ceased having any official status when the NI Parliament was dissolved in 1973. The origins of this flag is from the provisional arms of Ulster the most northern Irish province. According to legend the origin of the red hand of Ulster comes from a boat race in ancient times to decide who should become King of Ulster. The first to touch the shore would win. One potential king so desired the kingship that, upon seeing
that he was losing the race, cut off his hand and threw it to the shore thus winning the kingship. The star represents the provinces six counties and has no affiliation to the star of David. This flag is used by N.Irish sports teams (notably national football and Commonwealth games teams and sometimes for N.Irish golfers and snooker players) and private citizens. However the British Government sometimes use St Patrick's cross (as it is in the Union Jack) alongside the other three flags to represent N.Ireland, some sports teams also use St Patricks Cross(it also being less controversial than other flags). The NI district of the Boy's Brigade sometimes wear St Patrick's Cross on their uniform, but use the Ulster Banner on their website. The only official flag of Northern Ireland is the Union Flag, neither St Patrick's Cross or the Ulster Banner currently have any legal or official status in Northern Ireland.
Crown DependenciesBailiwick of Jersey
Bailiwick of Guernsey
Isle of Man
The flag of Mann is a triskelion of three armoured legs and has been the official flag of the island since 1931. It is a banner of theManx coat of arms which originally date from 13th Century. A triskelion is an ancient symbol, used by the Mycenaeans and the Lycians. It is not fully known why this was originally adopted as a symbol of the Isle of Man. Before 1931 the Union Flag was the only national flag of Mann.
Overseas Territories of the United KingdomThe United Kingdom has sovereignty over 13 overseas territories most of which have their own flag. Most (but by no means all) flags are derived from the local government ensign. The Sovereign bases of Akrotiri and Dhekelia don't have a unique flag of their own. The Union Flag is also the only flag of the Saint Helena, Ascension and Tristan da Cunha although each island has its own flag. The flags of the UK Overseas Territories are:
Diplomatic flags & other representatives of the SovereignThe plain old ordinary Union Flag is not always used as the national flag in UK diplomatic missions abroad. The flag may or may not be defaced depending on if the mission is an embassy, High Commission or Consulate:
The flag used British embassies and British Ambassadors to a sovereign state is the Union Flag defaced with the Royal Coat of Arms used by HM Government.
The Union Jack is used By British High Commissions
A Union Jack defaced with the State crown is used by British Consulates and Consular Generals to a foreign region.
When embarked on small boats, UK Consular and diplomatic officials may used a special Jack. This is a blue ensign with the royal coat of arms. This flag is flown from the bow and does not replace the vessels national colours whatever they be.
British Lord Lieutenants historically used the Union Flag, this led to legal confusion and confrontation as the Union Flag was also used by private citizens. Then in the early 1900s the Lord Lieutenant's flag was defaced with the crown and sword of state. This flag is used by HM Lord Lieutenants in England, Wales and Northern Ireland.
Representatives of the monarch including Lord Lieutenants in Scotland, use the Royal Banner with the lion rampant. This is due to differences in Scottish heraldry which allows arms to be used by representatives.
Governors of British Dependencies and Overseas Territories use a Union Jack Defaced with that territories coat of arms, in this example the coat of arms is that of the British Virgin Islands.
The Royal Standard is the most senior flag of the United Kingdom. It is the official flag of the reigning sovereign in the capacity of British monarch. The monarch uses other Royal Standards in her other realms. Although called the Royal Standard, it is in fact a heraldic banner of arms. It should only be used to denote the presence of the monarch and nothing else. Misuse of this flag can technically be treason! (although that charge almost defiantly wouldn't be prosecuted). Protocal dictates that the Royal standard should never be flown at half mast (not even for the death of the monarch) and should never share a pole with any other flag. The Union Flag is lowered in order to make way for this flag, thus making it the national flag if the monarch is present.
There are two variation of the Royal Standard. That used in England, Wales and Northern Ireland and when visiting non commonwealth countries(top), and that used in Scotland. (left).
Members of the Royal of the Royal Family who use variations of the Royal coat of arms also use a banner of arms, this is distinguished from The Royal Standard by the addition of labels and symbols along the top of the flag. For example the flag of Prince William (left)
Members of the Royal Family who do not have a coat of arms, may use a variation of the Royal Standard with an ermine boarder when fulfilling an official role. (Bottom) Each of these variations also have Scottish versions). For more information on the UK royal standard see here.
National Flags at Sea (ensigns and jacks)
Ensigns & National ColoursThe Union Flag is not used as the primary national flag at sea. Instead national ensigns are used these vary depending what category the vessel falls into or what warrant it or the corporate company that owns it may have. All UK ensigns have a Union Flag in the Canton.
British Civil Ensign/Red Ensign.
All vessels of the Merchant Navy and civilian vessels registered in the United Kingdom wear the red ensign (nicknamed the red duster) unless a warrant is granted from the Ministry of Defence (warrants were granted by the Admiralty, but this duty was taken over by the MoD when the Admiralty was merged into it) to deface it with a coat of arms/badge/logo or wear the Blue ensign. Civil vessels of UK dependencies and overseas territories wear a red ensign defaced with the territories coat of arms.
Examples of defaced Red Ensigns include the ensign used by vessels registered in the Isle of Man and West Mersea Yacht Club:
State Ensign/Blue Ensign
HM Coastguard, Police, HM Customs & Exiles, UK Boarder Agency, and vessels that are not commissioned warships but in naval service such as the Royal Fleet Auxiliary vessels, hospital ships and Warships going under sea trials (see emaple of HMS Duncan), before being formally commissioned. Some Yacht clubs also have warrants to use blue ensigns. Vessels of the local governments of Dependencies and Overseas Territories should use a blue ensign defaced with the relevant coat of arms. Some examples of State Ensigns include, Anguilla Government ensign and HM Coastguard:
Naval Ensign/White Ensign
HMY Britannia, or Royal Barge of the jubilee MV Spirit of Chartwell) and the Royal Yacht Squadron. The USS Winston Churchill is the only foreign vessel that has permission to use the White Ensign.
JacksThe use of the Union Jack at sea has been restricted since 1634, when King Charles I issued the fallowing decree, after disputes concerning saluting ships in the channel:
"A Proclamation appointing the Flags, as well for our Navy Royal as for the Ships of our Subjects of South and North Britain
"We taking into Our Royal consideration that it is meet for the Honour of Our own Ships in Our Navy Royal and of such other Ships as are or shall be employed in Our immediate Service, that the same be by their Flags distinguished from the ships of any other of Our Subjects, do hereby strictly prohibit and forbid that none of Our Subjects, of any of Our Nations and Kingdoms, shall from henceforth presume to carry the Union Flag in the Main top, or other part of any of their Ships (that is) S. Georges Cross and S. Andrews Cross joined together upon pain of Our high displeasure, but that the same Union Flag be still reserved as an ornament proper for Our own Ships and Ships in Our immediate Service and Pay, and none other.
"And likewise Our further will and pleasure is, that all the other Ships of Our Subjects of England or South Britain bearing flags shall from henceforth carry the Red-Cross, commonly called S. George his Cross, as of old time hath been used; And also that all other ships of Our Subjects of Scotland or North Britain shall henceforth carry the White Cross commonly called S. Andrews Cross, Whereby the several Shipping may thereby be distinguished and We thereby the better discern the number and goodness of the same. Wherefore We will and straitly command all Our Subjects forthwith to be conformable and obedient to this Our Order, as they will answer the contrary at their perils.
"Given at Our Court at Greenwich this fifth day of May in the tenth year of our Reign of England Scotland France and Ireland, Defender of the Faith &c"
In short this means that the Union Flag was restricted to naval vessels making the Union Jack the UK's naval jack:
However not all ships in state service use the Union Jack. The Royal Fleet Auxiliary use a square version of their ensign:
Other ships in state service may use the Government Service Jack which is a square version of Government Service Ensign similar to the RFA jack but with a horizontal anchor.
Corporate ships normally use the company house flag as a jack, but for those private vessels that wish to display their national flag, a special civil jack is available. Thus allowing private vessels to fly the Union Jack but at the same time not risk a fine form the harbour master:
This civil jack is a Union Flag with a white boarder to distinguish it from the naval jack.
National Flag at, Airports and Military establishments
Army establishments should use the Union Jack as their national flag, and Royal Navy shore establishments (including Royal Marines Bases) should use the White Ensign as their national flag (most navy bases are commissioned as ships but even those which aren't still use it). Royal Air Force Bases should use the RAF ensign as their national flag:
This is a sky blue ensign defaced with the air force aircraft roundel.
Civilian airports should not use the Union Jack as their national but instead use the Civil Air ensign:
Similar to the RAF ensign but defaced with a blue cross rather than a roundel. This should be flown as the national flag at airports and should also be the flag painted on UK registered civil aircraft (the Union Flag is used on some military aircraft). Alternatively airports may use the flag of the region of the United Kingdom they are in. This is one of the less well known UK flags and is one I personally don't recall seeing either on a plane or airport. I do however recall that London Stansted Airport flies the Union Jack outside the terminal building apparently in breech of protocol.
What about Wales?
Wales has no representation in the Union Jack due to it being a region of England when it was first introduced. There have been proposals to introduce Welsh symbolism into the flag. In 2007 Ian Lucas MP debated in the House of Commons that a red dragon be added to the union Flag. This was unpopular and is probably unfeasible. To quote one YouTube user "You can't put a dragon on the cross of a dragon slayer!" However other better thought out proposals include changing the blue at the bottom to green to reflect the Welsh flag, or even better incorporating the cross of St David:
Possible flag of the future?
As always comments are welcome