The Iberians, among Britain's earliest known inhabitants, mined
tin in Cornwall, manufactured bronze tools, and enjoyed widespread
trade with the European continent. They also left behind Europe's
most spectacular example of megalithic engineering, Stonehenge,
built between 3000 and 1000 BC.
Britons may have initially resented the occupation, but gradually
accepted Roman civilization. Although Romans ruled southern Britain
for more than 400 years, they never conquered the other tribes in
the northern third of the island, a region they called Caledonia.
To defend from Caledonian invasions, in AD 122 the emperor Hadrian
ordered that a wall be built between the Solway Firth and the Tyne
River estuary, a distance of 119 kilometers (74 miles). Parts of
Hadrian's Wall still stand.
The devastation of WWI, in which a third of all British men were
killed, led to the emancipation of women, who were allowed to vote
in 1918 and who now formed a significant part of the workforce.
Ireland won independence in 1921 after a protracted war.
In 1931, Great Britain attempted to bolster its crumbling empire
by creating the British Commonwealth of Nations, a federation of
countries and dependencies ceremonially linked under the British
Crown. The end of WWII sparked widespread nationalist movements
in the colonies, most of which achieved independence by the 1960s.