The national flag of the United Kingdom was instituted in 1801 following the "Act of the Union" which united the Kingdom of Great Britain and the Kingdom of Ireland to form the United Kingdom of Great Britain and Ireland. The flag comprises the red cross of St George (the patron saint of England) outlined in white and superimposed on the Cross of St Patrick (patron saint of Ireland) which consists of a red saltire on a white background. Once combined, the design is then superimposed on the St Andrew's Cross (the patron saint of Scotland) which consists of a white saltire on a blue background. Wales is not represented on the flag as it was part of the Kingdom of England when the flag was designed. The official Order in Council which created the new flag of the United Kindgom in 1801 described the flag as follows - "The Union Flag shall be azure, the Crosses saltire of Saint Andrew and Saint Patrick quarterly per saltire, counter-changed, argent and gules, the latter fimbriated of the second, surmounted by the Cross of Saint George of the third fimbriated as the saltire."
The flag of the United Kingdom is often referred to as the "Union Jack" or the "Union Flag". The flag's proportions are 1:2.
The flag of the United Kindgom may be flown by any individual or organisation on any day of the year. The government has directed that the flag be flown at half-mast in the following situations:
- from the announcement of the death of the Sovereign
- the day of the funeral of a member of the British Royal Family
- the funeral of a foreign Head of State
- the funeral of a former British Prime Minister
There has been some public debate about the possibility of including some representation of Wales on the United Kingdom flag (for example, the Welsh Dragon); however, this has not yet come to pass.
The flag of the United Kindgom - the 'Union Jack' - flies in London