The Kingdom of Great Britain was created by the merger of the Kingdoms of England and Scotland in 1707 (see 1707 Act of Union). A single parliament and government, based in Westminster in London, ran the entire kingdom. They had shared a monarch since King James VI of Scotland became King James I of England in 1603.
From 1707, a joint 'British' throne replaced the English and Scottish thrones and a joint Parliament of Great Britain replaced the Scottish and English parliaments. Scotland and England were given seats in both the House of Commons and the House of Lords of the new Parliament, although Scotland's representation in both houses was smaller than her population indicated that it should have been.
See also: Flag of the United Kingdom.