I'm not across the pond but I can answer this for you.
Great Britain is an island that lies northwest to continental Europe. That landmass contains three countries: England, Wales and Scotland, which were originally all independent of each other. Wales fell under English control in the 13th century.
England and Scotland have shared a monarch since 1603 when Queen Elizabeth I died. She never married and did not produce an heir, so her cousin King James VI of Scotland became King James I of England upon her death. England and Scotland remained two separate kingdoms for a little over 100 years. The Acts of Union in 1707 merged the two kingdoms into one -- the Kingdom of Great Britain, during the reign of Queen Anne.
Ireland had long been under English control; it remained a separate kingdom until 1800, when another Act of Union was passed, dissolving the Irish parliament, and absorbing it into the Kingdom of Great Britain. It was about this time that the political union began being referred to as the United Kingdom of Great Britain and Ireland.
Ireland won the right to Home Rule in 1921 when the Irish Free State was formed. Northern Ireland was given the right to opt out of the Home Rule Treaty and so the country was partitioned. The Irish Free State became the Republic of Ireland in 1949 when it seceded from the UK. From that point on, the UK became known as the United Kingdom of Great Britain and
Northern Ireland.
Currently there is a faction in Scotland that favors secession from the UK. How the country's name would change if that were to happen is not clear.
I think I've got all the main points right, but if not I'm sure some of our members from across the pond can set the record straight.
