Settlement by humans of what was to become the United Kingdom occurred in waves beginning by about
30.000 years ago. By the end of the region's prehistoric period, the population is thought to have belonged, in the
main, to a culture termed Insular Celtic, comprising Brythonic Britain and Gaelic Ireland.
The Roman conquest, beginning in 43 AD, and the 400-year rule of southern Britain, was followed by an invasion by
Germanic Anglo-Saxon settlers, reducing the Brythonic area mainly to what was to become Wales.
Most of the region settled by the Anglo-Saxons became unified as the Kingdom of England in the 10th century.
Meanwhile, Gaelic-speakers in north west Britain united with the Picts to create the Kingdom of Scotland in the
9th century.
In 1066, the Normans invaded England and after its conquest, seized large parts of Wales, conquered much of
Ireland and settled in Scotland. Subsequent medieval English kings completed the conquest of Wales and made an ultimately
unsuccessful attempt to annex Scotland. Thereafter, Scotland maintained its independence, albeit in near-constant
conflict with England.
The English monarchs, through inheritance of substantial territories in France and claims to the French crown, were
also heavily involved in conflicts in France, most notably the Hundred Years War.
In 1603, the kingdoms of England, Scotland and Ireland were united in a personal union when James VI, King of
Scots, inherited the crowns of England and Ireland and moved his court from Edinburgh to London; each country
nevertheless remained a separate political entity and retained its separate political institutions.
The unified kingdom of Great Britain came into being on 1 May 1707, the result of Acts of Union being passed by
the parliaments of England and Scotland. The term 'United Kingdom' became official in 1801 when the parliaments
of Britain and Ireland each passed an Act of Union, uniting the two kingdoms and creating the United Kingdom of
Great Britain and Ireland.
After the defeat of France in the Revolutionary and Napoleonic Wars (1792–1815), the UK emerged as the principal naval
and imperial power of the 19th century (with London the largest city in the world from about 1830) The British Empire
was expanded to include India, large parts of Africa, and many other territories throughout the world.
In 1919, the majority of Irish MPs refused to recognise the Parliament of the United Kingdom and formed a
unilaterally independent Irish parliament. A War of Independence was fought between 1919 and 1921. Finally
in December 1922, twenty-six of Ireland's counties exited from the United Kingdom of Great Britain and Ireland and
formed an independent Irish Free State. The southern part of Ireland that seceded from the union is today the
Republic of Ireland. Six counties of Ireland, called Northern Ireland, remained a part of the continuing
United Kingdom, which was renamed the United Kingdom of Great Britain and Northern Ireland.