While maintaining separate parliaments, England and Scotland were ruled under one crown beginning in 1603, when James VI of Scotland succeeded his cousin Elizabeth I as James I of England. In the ensuing 100 years, strong religious and political differences divided the kingdoms. Finally, in 1707, England and Scotland were unified as Great Britain, sharing a single Parliament at Westminster.

Great Britain, also referred to as the Kingdom of Great Britain, was a monarchy established by the Act of Union on May 1, 1707 that politically united the kingdoms of England and Scotland.

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