It wasn't called anything before being called the UK. It did not exist then.
Brittania
In Britain, it was called "Pop Idol".
The people who lived in Britain before the Romans belonged to various tribes under local warlords, such as the Iceni, the Belgae, the Dobunni, etc.
allies
Britain was made to be called Britain when sex arrived
Britain was called Britannia by the Romans.Britain was called Britannia by the Romans.Britain was called Britannia by the Romans.Britain was called Britannia by the Romans.Britain was called Britannia by the Romans.Britain was called Britannia by the Romans.Britain was called Britannia by the Romans.Britain was called Britannia by the Romans.Britain was called Britannia by the Romans.
Britain.
England, Scotland and Wales. The full name of the UK is "The United Kingdom of Great Britain and Northern Ireland" because it is just that, a united kingdom of four separate countries/principalities. Britain is actually just the big island containing England, Scotland and Wales.
It's simply called "Britain's Got Talent"
The country is called the United Kingdom of Great Britain and Northern Ireland. The island is called Great Britain.
After Hitler's early victories to conquering, they now had mainland Europe and now Britain was next. But before they could invade, they had to get air superiority. So they sent a fleet of fighters/bombers to intercept the RAF. This battle was called the Battle of Britain.
In 1900 the country colloquially called Britain (or, infuriatingly, England by many Americans) was called: The United Kingdom of Great Britain and Ireland.