The Kingdom of Great Britain was a sovereign state in Western Europe from 1707 to the end of 1800. The state was created by the 1706 Treaty of Union and ratified by the Acts of Union 1707, which united the kingdoms of England and Scotland to form a single kingdom encompassing the whole island of Great Britain and its outlying islands, with the exception of the Isle of Man and the Channel Islands. The unitary state was governed by a single parliament at the Palace of Westminster, but distinct legal systems—English law and Scots law—remained in use.

The Acts of Union were two Acts of Parliament: the Union with Scotland Act 1706 passed by the Parliament of England, and the Union with England Act 1707 passed by the Parliament of Scotland. They put into effect the terms of the Treaty of Union that had been agreed on 22 July 1706, following negotiation between commissioners representing the parliaments of the two countries. By the two Acts, the Kingdom of England and the Kingdom of Scotland—which at the time were separate states in a personal union—were, in the words of the Treaty, "United into One Kingdom by the Name of Great Britain".