Why is the British Flag Called the Union Jack?

The flag of the United Kingdom, often known as the "Union Jack".
The flag of the United Kingdom, often known as the "Union Jack".

Aside from the Union Flag or the Royal Union Flag (in Canada), the national flag of the United Kingdom is also commonly known as the Union Jack. Aside from the UK, the Union Jack is also the official flag of British Overseas Territories. In addition, the flag appears on the upper left-hand region of the flags of some countries, especially those that were once colonies of Britain. The flag’s design dates all the way back to 1603 during the reign of King George III. The design of the Union Jack features three symbols, namely the red cross of Saint George, the Saltire of Saint Andrew, and the Cross of St Patrick, which is also red. All these three symbols, which represent England, Ireland, and Scotland, are on a blue background.


The naming of the flag can be traced back to the 17th century after the demise of the monarch who was Queen Elizabeth I of England in 1603. At that time, the kingdoms of England and Scotland had not been united. At the time of her death, Elizabeth I did not leave any heirs since she had not been married. King James VI of Scotland was the only surviving heir and, therefore, became the next king of England. The ascension of James VI saw to it that the two kingdoms had a similar monarch, which is why his ascension was called the union of the crowns.

A few years after his ascension in 1606, King James VI issued a decree for the creation of the British flag. Since there were only two kingdoms under his leadership, he decreed that the flag had to have both the crosses of St. Andrew and St. George to represent Scotland and England respectively. The resulting flag that was designed was one of the first designs of the Union Jack. However, it is important to note that when the flag was first released, it was not known as the Union Jack or the Union Flag. Instead, it was simply known as the flag of Britain or the British flag. The royal decree from the king did not state that the flag had to be called the Union Jack.

Possible Theories for the Origin of "Union Jack" 

One of the most popular theories is that the nickname originated from naval usage. This theory has been disputed in recent times after more investigations. However, it is important to note that the maritime bow flag was commonly known as the “jack” even before the flag was designed. During the union of 1801, there were several mentions of the flag that were made by the king. The flags at sea were known by several names such as pendants, ensigns, flags, and jacks. This theory most likely arose from these proclamations.

Another possible theory could have been the international reputation of the British Royal Navy since most British ships used the term “jack” to refer to flags. Over the years, the name was also popularized by political figures such as Winston Churchill who was the Prime Minister of the UK between 1940 and 1945.


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