The United Kingdom is made up of four main countries, England, Wales, Scotland and Northern Ireland.
The UK flag is called the Union Flag.
The flag is actually three flags in one. It is made up from the England flag, the Scotland flag and the patron saint of Ireland's Flag.
England is represented by the flag of St. GeorgeIn 1194 A.D., Richard I of England introduced the Cross of St. George, a red cross on a white ground, as the the national flag of England until James I succeeded to the throne in 1603.
In 1606, Scotland is represented by the flag of St. Andrew(a diagonal white cross on a blue background.)
When King James VI of Scotland became King James I of England a new flag combining the white on blue cross of St Andrew, with the red cross of St George, was adopted by the Royal Navy and christened the " The Union" in 1707.
When the red cross of England was put onto the flag of Scotland, a white border was added around the red cross for reasons of heraldry.
Ireland is represented by the flag of St. Patrick(a diagonal red cross on a white background.)
In 1801, after the Union with Ireland, King George III added the cross of St Patrick to the Union flag, to make the Union Jack we have today.
The formation of the Union Jack came about as the result of the progressive merging of the inhabitants of the British Isles under one throne