Today is the 400th birthday of the Union Flag (should really only be called Union Jack when it's on a British ship). On 12th April 1606, King James I of England, VI of Scotland (a Scotsman) created the first ever Union Flag after he went through many trial designs - even though Scotland wasn't actually a part of Britain at that time (it was just the Crowns that were united).
The current flag (with the red diagonal cross incorporated onto it) dates only from 1801 when Ireland became a part of Britain (in those days, Ireland's flag was a red, diagonal cross on a white background). The cross is still on the flag because it represents Northern Ireland, since the rest of Ireland left Britain in 1922, even though NI has a new flag of its own. Wales' flag, which has a red dragon, is not included in the Union Flag as it was already united with England before 1606.
The blue background is, of course, from Scotland's flag, although it is dark blue on the Union Flag but light blue on the Saltire.
The Union Flag before 1801
When James VI of Scotland inherited as James I of England in 1603, the crowns of the Kingdom of England and the Kingdom of Scotland were united in him, although each remained independent states.
On 12 April 1606, a new flag to represent this personal union between England and Scotland was specified in a royal decree, according to which the flag of England (a red cross with a white background, known as St George's Cross) and the flag of Scotland (a white saltire with a blue background, known as the Saltire or Saint Andrew's Cross) would be "joyned together according to the forme made by our heralds, and sent by Us to our Admerall to be published to our Subjects." The original sketches which accompanied this specification are lost. This royal flag was at first only for use at sea on civil and military ships of both Scotland and England. In 1634, its use was restricted to the monarch's ships. Land forces continued to use their respective national banners.
After the Acts of Union 1707, the flag gained a regularised status, as "the ensign armorial of the (United) Kingdom of Great Britain", the newly created state. It was then adopted by land forces as well.
Various shades of blue have been used in the Saltire over the years. The ground of the current Union Flag is a deep "navy" blue (Pantone 280), while the currently accepted Saltire uses a lighter "royal" blue (Pantone 300), following the Scottish Parliament's recommendation of 2003.
Wales had no explicit recognition in the flag because Wales had been annexed by Edward I of England in 1282, and since the Laws in Wales Acts 1535-1542 was considered to be a part of the Kingdom of England. (The present-day Flag of Wales and St David's Cross are both 20th century inventions, the former based on a Royal badge and the latter on the arms of the Diocese of Saint David's.) The Kingdom of Ireland, which had existed as a personal union with England since 1541, was also not represented in the original Union Flag.
The pre-1801 Union Flag is also shown in the canton of the Grand Union Flag (also known as the Congress flag, The First Navy Ensign, The Cambridge Flag, and The Continental Colors), the first widely-used Flag of the United States.
The blazon for the old flag, to be compared with the current flag, is Azure, the Cross Saltire of St Andrew Argent surmounted by the Cross of St George Gules, fimbriated of the second.
The current Union Flag dates from 1 January 1801 with the Act of Union 1800, which merged the Kingdom of Ireland and the Kingdom of Great Britain to form the United Kingdom of Great Britain and Ireland. The new design added the red saltire cross attributed to St Patrick for Ireland. This saltire is overlaid on the saltire of St Andrew. The red cross is thought to have come from the heraldic device of the Fitzgerald family who were sent by Henry II of England to aid Anglo-Norman rule in Ireland and has rarely been used as an emblem of Ireland by the Irish: a harp, a Celtic cross, a shamrock, or (since 1922) an Irish tricolour have been more common. However, the exact origin of the flag is unknown, with evidence of saltires being present on ancient Irish coins and maps. The St Patrick's saltire flag has been used in more recent times for St Patrick's Day in Northern Ireland, by various organisations wishing to avoid the sectarianism that may be implied by the use of either the tricolour or symbols of Unionism.
The current flag is blazoned Azure, the Crosses Saltire of St Andrew and St Patrick, quarterly per saltire, counterchanged Argent and Gules, the latter fimbriated of the second, surmounted by the Cross of St George of the third, fimbriated as the saltire.
Other proposed versions
Other proposed versions.Various other designs for a common flag were drawn up following the union of the two Crowns in 1603, but were rarely, if ever, used. The two shown here include St George's cross with St Andrew's cross in the canton, and another version where the two crosses are side-by-side. Also, some Scots were upset that the Scottish flag was underneath the English flag in the version finally adopted, and preferred a version where the Scottish cross was on top (the English flag was placed between the cross of St Andrew and its background).
Many Welsh people have proposed modifying the Union Flag to include either the Red Dragon or the black and gold colours of the flag of Saint David, arguing that the current design fails to represent their nation.
No law has ever been passed making the Union Flag the national flag of the United Kingdom; rather it has become one through usage. Its first recorded recognition as a national flag came in 1908, when it was stated in Parliament that "the Union Jack should be regarded as the National flag". A more categorical statement was made by the Home Secretary in 1933, when he stated that "the Union Flag is the National Flag".
Civilian use is permitted, but stricter guidelines apply for use on naval vessels where the flag may not be used as a jack by merchant ships (see below). Interestingly, unauthorised use of the flag in the 17th Century to avoid paying harbour duties - a privilege restricted to naval ships - caused James' successor, Charles I, to order that use of the flag on naval vessels be restricted to His Majesty's ships "upon pain of Our high displeasure". Those restrictions remain, and still today it is a criminal offence to fly the union jack from a boat.
The Court of the Lord Lyon, which has criminal jurisdiction in heraldic matters in Scotland, confirms that 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."
The Union Flag has been in usage in Canada dating back to the British settlement in Nova Scotia in 1621. At the close of the Great Flag Debate of 1964, which resulted in the adoption of the Maple Leaf Flag as the Canadian national flag, the Parliament of Canada voted to keep the Royal Union Flag as an official flag of Canada and as the symbol of Canada's membership of the Commonwealth and her allegiance to the Crown. It is commonly flown alongside the Maple-Leaf Flag on Commonwealth Day and other royal occasions and anniversaries.
Other nations and regions
The Union Flag was found in the canton (top left-hand corner) of the flags of many colonies of the UK, while the field (background) of their flags was the colour of the naval ensign flown by the particular Royal Navy squadron that patrolled that region of the World.
All administrative regions and territories of the United Kingdom fly the Union Flag in some form. Outside the UK itself, it is usually part of a special ensign in which the Union Flag is placed in the upper left hand corner of a blue field, with a signifying crest in the bottom right.
Four countries currently incorporate the Union Flag as part of their own national flags: Australia, New Zealand, Tuvalu, and Fiji. In former British colonies, the Union Flag was used semi-interchangeably with territorial flags for significant parts of their early history. This was also the case in Canada until the introduction of the Maple Leaf Flag in 1965, but it is still used in the flags of a number of Canadian provinces like British Columbia, Manitoba and Ontario. It is also shown in the canton of the Flag of Hawaii, for quite different reasons. The Miskito people sometimes use a similar flag that also incorporates the Union Flag in its canton, due to long periods of contact in the Mosquito Coast.