I am a bit of a stickler for correct usage of styles and titles. So it is a bit of a pet peeve of mine when these are used improperly. There has been talk on this site about how the press, typically in the US, still refers to HRH The Duchess of Cambridge by her maiden name, Kate Middleton. The main misuse of titles that bothers me is calling Elizabeth II, Queen of England. That bothers me because “Queen of England” is not her correct title! Her correct title, simplified here, is Queen of the United Kingdom of Great Britain and Northern Ireland. England has not been a separate sovereign state since 1707.
Here is a little historical background on the issue. For centuries England and Scotland were separate sovereign kingdoms each with their own monarch. There was not always peace between the two states and England constantly tried to keep Scotland subdued. Edward I (1272-1307) is not known as the Hammer of the Scots for nothing! The Kingdoms of England and Scotland remained separate until 1603. Queen Elizabeth I of England died without issue and her closest relative that had a claim to the throne was her cousin James VI, King of Scots (1567-1625).
The accession of the Scottish king on the English throne did not politically unite the two nations. Both kingdoms were ruled by James but remained individual sovereign states that retained their own parliaments and laws. Although James liked to consider himself the King of Great Britain this title had no legal barring. From 1603 until 1707 (excluding the Commonwealth period) the title of the monarch was King or Queen of England and Scotland (they also called themselves the Kings of France but that is another story). In 1707 came the Act of Union uniting the Parliaments of England and Scotland creating the new nation of Great Britain. England and Scotland ceased to be independent sovereign states and were then, and now, considered separate states within the union. The title of the monarch changed accordingly and the titles of King or Queen of England and Scotland passed into history. Anne was Queen of England and Queen of Scots when the act was passed and her title was changed to Queen of Great Britain.
The title remained King or Queen of Great Britain for 93 years until the nation expanded once more. Ireland was included in the political union with Great Britain and the new state became the United Kingdom of Great Britain and Ireland. George III (1760-1820) was the monarch at the time and his title changed accordingly. From 1714 to 1837 The British monarch were also Electors and then Kings of Hanover (1814). Though their Hanoverian titles were listed among their British title, Britain and Hanover were ruled separately and were not politically unified.
In 1920 in the reign of King George V (1910-1936) a large portion of Ireland was given its independence and only the northern counties remained united with Britain. From that time until the present the title of the monarch has been King or Queen of the United Kingdom of Great Britain and Northern Ireland.
Now having given the historical background on the evolution of the title of the British monarch I must be honest and say that I do miss the traditional titles of King or Queen of England and King or Queen of Scots. Those are in the past unless devolution comes to the UK and England and Scotland becomes independent once again. If that does happen I think we would see a return to how things were prior to 1707 when both England and Scotland shared the same monarch.