Photo: Joe Maher/Getty

Band of the Coldstream Guards play during the State Funeral of Queen Elizabeth II on September 19, 2022 in London, England. Elizabeth Alexandra Mary Windsor was born in Bruton Street, Mayfair, London on 21 April 1926.

The Union Jack, also known as the Union Flag, is the national flag of the United Kingdom of Great Britain and Northern Ireland, the Crown Dependencies and the Overseas Territories, and is rooted in a 400-year history.

It is largely associated with ideals of pride and patriotism, which is why the flag has been proudly scattered and sported among thetens of thousands of spectatorswho have lined the streets to celebrateQueen Elizabeth II’s long life and reign following her death.

While theRoyal Standard flag was draped over Her Majesty’s coffinduringthe funeral and several processions, it differs from the Union Jack in that it represents the Sovereign and the United Kingdom.

Both flags were notably used to signify theQueen’s presence in Buckingham Palace. The Royal Standard would only fly when she was there, while the Union Jack would fly when she was not.

In the wake ofthe Queen’s death, the Union Jack is to be flown at half-mast. (The Royal Standard is never flown at half-mast— “even after the death of a monarch, as there is always a Sovereign on the throne.")

From the Union Jack’s origin to the meaning behind its multiple crosses, here’s everything to know about the United Kingdom’s national flag.

Which countries does the Union Jack flag represent?

Hollie Adams/Bloomberg via Getty

A Royal Guard marches along The Mall ahead of the state funeral of Queen Elizabeth II, in London, UK, on Monday, Sept. 19, 2022. The Queen’s life is commemorated at her state funeral in Westminster Abbey in London, to be attended by roughly 500 global dignitaries and world leaders including US President Joe Biden.

The Union Jack flag is the national flag of the United Kingdom. It represents the four countries that are united under one Sovereign, including England, Wales, Scotland and Ireland — though since 1921, only northern Ireland has remained a part of the United Kingdom.

In addition, commonwealth countries have incorporated the Union Jack within their flags to signify the history of British settlement, including Australia, New Zealand, and Tuvalu.

Furthermore, the U.S. state of Hawaii, several Australian states (New South Wales, Queensland, South Australia, Tasmania, Victoria, and Western Australia), and three Canadian provinces (British Columbia, Manitoba, and Ontario) feature Union Jack on their flags.

Why is the United Kingdom’s national flag called Union Jack?

Ed Ram/Getty

Crowds gather on The Mall near Buckingham Palace to watch the funeral of Queen Elizabeth II on September 19, 2022 in London, England. Elizabeth Alexandra Mary Windsor was born in Bruton Street, Mayfair, London on 21 April 1926. She married Prince Philip in 1947 and ascended the throne of the United Kingdom and Commonwealth on 6 February 1952 after the death of her Father, King George VI. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III.

There is much debate about the exact origin of the Union Jack flag’s name. In the 16th century, it was initially called the British flag and in 1625,the word “Union” was introduced.

When the flag was first created in 1606, it was ordered primarily to fly at sea, situated atop the main masthead of all English and Scottish ships, warships and merchant ships. Before the 1600s, the term “jack” was used to describe asmall flag flown at the bow of a ship.

Some believe the “Union Jack” title dates back to Queen Anne’s reign from 1702 to 1714, per the royal family’sofficial website. Others believe it derives from the “jack-et” of the English or Scottish soldiers, or from the name of James I who formed the first union in 1603.

What do the colors and crosses on the Union Jack flag represent?

Zac Goodwin - WPA Pool/Getty

The State Gun Carriage carries the coffin of Queen Elizabeth II, draped in the Royal Standard with the Imperial State Crown and the Sovereign’s orb and sceptre, in the Ceremonial Procession following her State Funeral at Westminster Abbey on September 19, 2022 in London, England.

The Union Jack consists of three heraldic crosses combined: Saint George’s Cross of England, Saint Andrew’s Cross of Scotland and Saint Patrick’s Cross of Ireland. The layout of the flag has evolved since the first Union Flag — which is what it was initially known as — was created in 1606.

The first Union Flag only consisted of England’s red cross of Saint George on a white background combined with Scotland’s white diagonal cross on a blue background. But since it isnot considered permissibleto have red on a blue background, according to heraldry, the red cross had to be bordered with white.

Can’t get enough ofPEOPLE’s Royals coverage?Sign up for our free Royals newsletterto get the latest updates onKate Middleton,Meghan Markleand more!

When is the Union Jack flag flown?

Dan Kitwood/Getty

Horse Guards Parade after the State Funeral of Queen Elizabeth II along The Mall on September 19, 2022 in London, England.

Initially, the Union Flag was recognized as a Royal Flag. When its present design was deemed official in 1801, it wasordered to be flown solelyon all the King’s forts and castles.

“The Royal Standard is never flown at half-mast, as the Sovereign never dies (the new monarch immediately succeeds his or her predecessor),” the royal family’sofficial websitestates.

Government buildings must fly the Union Jack flag on Royal Family birthdays, Commonwealth Day, Coronation Day, The Queen’s official birthday, Remembrance Day and on the days of the State Opening and prorogation of Parliament.

In more recent years, U.K. government buildings have been encouraged to fly the flagall year round. In the wake of the Queen’s death, the Union Jack flag — in addition to all official flags —should be lowered to half-masteduntil 8 a.m. on the day after the Queen’s state funeral.

source: people.com