Country profile – United Kingdom

Today's Union Jack is the result of two successive mergers. In 1606, three years after the union of the English and Scottish crowns under James VI of Scotland, who became James I of England, a first flag combined the red cross of St George, patron saint of England, on a white field, with the white saltire of St Andrew, patron saint of Scotland, on a blue field.

Wales does not appear on this flag: conquered by England as early as the thirteenth century and formally incorporated into the kingdom by the Laws in Wales Acts of 1535 and 1542, it was no longer a separate kingdom by 1606.

The current design dates from 1 January 1801, when the Act of Union merged the Kingdom of Great Britain with the Kingdom of Ireland. St Patrick's red saltire, representing Ireland, was then added to the design, offset from St Andrew's saltire so that neither country would appear to take precedence over the other.

• Red cross of St George (white field): represents England.
• White saltire of St Andrew (blue field): represents Scotland.
• Red saltire of St Patrick: represents Ireland, today mainly Northern Ireland within the United Kingdom.

Wales remains absent from the flag, having already ceased to be a separate kingdom by the time the original Union Jack was created in 1606. This omission still fuels regular debate about a possible redesign that would include the Welsh red dragon.

St Patrick's saltire is not centered on St Andrew's: the red and white bands are slightly offset, a heraldic technique known as "counterchange," so that neither kingdom appears to be placed above the other.

The flag has a correct way up: the broader white diagonal band of St Patrick's saltire should sit above the red band in the upper hoist canton. Flying it upside down is traditionally a distress signal, though the mistake usually goes unnoticed today.

The origin of the name "Union Jack" is still debated: it may come from the nautical term "jack," a small flag flown at a ship's bow, or from the Latinized name of King James I, Jacobus, who presided over the first union of the crowns in 1603.