On 28th July, 1707, during the reign of Queen Anne, the Union Flag was by royal proclamation made the National flag of Great Britain. The National Flags of Scotland and England were united to form the flag.
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. (The rules of heraldry demanded that two colours must never touch each other.)
Today's Union Flag not only represents Great Britain (England, Wales and Scotland) but also Northern Ireland.
On 1 January 1801, Ireland was united with Great Britain and it became necessary to have a new National Flag in which Ireland was represented. The cross St Patrick was combined with the Union Flag of Great Britain, to create the Union Flag that has been flown ever since.
United Kingdom of Great Britain and Ireland
England, Wales, Scotland and Ireland were all joined together and called the United Kingdom of Great
Britain and Ireland.
Britain and Ireland.
United Kingdom of Great Britain and Northern Ireland
The name was later changed to United Kingdom of Great Britain and Northern Ireland when the greater part of Ireland left the United Kingdom in 1921.