The United Kingdom was formed in 1801 when an Act of Union brought Ireland under the same parliament with England, Scotland and Wales. The official name of the country was changed to the United Kingdom of Great Britain and Ireland. But 26 Irish counties left the Union in 1922 and formed the Irish Free State, now the Republic of Ireland. Five years later the Royal and Parliamentary Titles Act named the union as the United Kingdom of Great Britain and Northern Ireland.
Wales was the first to unite with England, having been subdued by King Edward I in 1282. The heir to the English throne has been known as the Prince of Wales ever since Edward gave the title to his baby son in 1301. But it was not until 1536 when Henry VIII, a Tudor monarch of Welsh descent, was on the throne, that an Act of Union peacefully incorporated the Principality into the kingdom. The name Great Britain came into the use after James VI of Scotland succeeded to the English throne in 1603 as James I and united the two crowns, though not the nations. Another act of Union brought England and Scotland under one government in 1707.
The Union flag of the present kingdom is composed of the flag of England (white with an upright red cross), the flag of Scotland (blue with a diagonal white cross) and the red diagonal cross of Ireland. On May 29, 1953, under the Royal Titles Act, a proclamation was issued which gave Queen the title: Elizabeth the Second, by the Grace of God, of the United Kingdom of Great Britain and Northern Ireland and of her other Realms and Territories Queen, Head of the Commonwealth, Defender of the Faith.