The Union Flag or Union Jack Flag is the official flag of the UK which includes Northern Ireland.
It is also used extensively in Commonwealth countries.
Why is it called Union Jack?
It is called the Union Flag because the United Kingdom is a union England, Scotland, Wales and Northern Ireland.
Union Jack History continued
The concept of a Union Flag matured in 1603 when James VI of Scotland inherited the throne of England as James I. In this way, the kingdoms of Scotland and England were united in the person of James (though they were officially united in 1707)..
In 1606 the first Union Flag appeared. It was a combination of two flags. First, the red cross on a white background is known as the Cross of St. George and was the official flag of England. Second, the white X shaped cross (known in heraldry as a “saltire” on a blue background and known as the Cross or Saltire of St. Andrew, the official flag of Scotland.
The first Union Flag was the Cross of St. George superimposed on the Saltire of St. Andrew. You can see this in the diagram below where the two top flags created the first flag on the second row.
What about Ireland?
Ireland had been annexed to England in 1542 so it did not appear in the Union Flag. It was considered as represented by the Cross of St. George.
However, this changed in 1801. In the Act of Union 1801 Ireland (which was still fully under British rule) joined the Union on the same footing as England and Scotland. Ireland's flag, a red X shaped cross on a white background and known as the Cross or Saltire of St. Patrick, was added.
And so the Union Flag, as we know it today, took its form.
What about Wales?
Wales had been annexed to England in 1282 and like Ireland, was initially considered as represented in the Union Flag through the Cross of St. George.
During the 20th century there have been calls for greater autonomy for Wales and, recently, a call that Wales be represented in the Union Flag.
The Flag of Wales consists of a Red Dragon passant (striding) on a green and white background.
If the Red Dragon is incorporated into the Union Flag, it might look something like this:
Other flags that can be flown officially in Northern Ireland are: