The United Kingdom of Great Britain and Northern Ireland lies at the northwestern edge of Europe, separated from the European mainland by the English Channel, the North Sea, and the narrow Strait of Dover. It consists of the formerly separate kingdoms of England and Scotland and the principality of WalesÑwhich are collectively referred to as Great BritainÑand the six counties of Northern Ireland, which elected to remain within the United Kingdom in 1921 when southern Ireland withdrew to form the Irish Free State (after 1949, the Republic of Ireland, or Eire). The loss of Ireland and its withdrawal from the Commonwealth of Nations in 1949 rendered politically obsolete the use of the collective term British Isles. Other integral parts of the United Kingdom are the outlying Hebrides, Orkney Islands, and Shetland Islands, off the coast of Scotland; Anglesey (see Gwynedd), off the coast of Wales; and the Isle of Wight and the Scilly Isles, off the southwest coast of England. Separate from the kingdom but administered by the crown, each with its own laws and systems of taxation, are the Isle of Man, located in the Irish Sea; and the Channel Islands, located off the northwest coast of France.
England is the largest and most populous unit in the kingdom, with an area of 130,439 Ü (50,363 æ) and a population (1994 est.) of 48,707,500. Wales, located to the west and separated from England by a boundary dating back to the Middle Ages, has an area of 20,768 Ü (8,018 æ) and 2,913,000 inhabitants; it became part of the English kingdom in 1282 but continues to maintain a separate language and national identity. ScotlandÑwith an area of 78,772 Ü (30,414 æ) and 5,132,400 inhabitantsÑlies to the north, separated from England by a boundary that extends from Solway Firth (estuary) on the west, across the sparsely populated Cheviot Hills, to the north of Berwick upon Tweed. Scotland and England were ruled by the same monarchs after 1603 and were united in 1707 to form the kingdom of Great Britain. Ireland was made an integral part of the kingdom in 1801, changing the official name to the United Kingdom of Great Britain and Ireland. The present name was adopted after the partition of Ireland in 1921. Northern Ireland has an area of 14,121 Ü (5,452 æ) and a population of 1,641,700.
Commonly described as "in Europe but not of it," Great Britain and Ireland remained relatively isolated from world events until the 15th century when the Age of Discovery placed them on the world's newly charted sea-lanes and trading routes. Increasingly, the island nation looked away from Europe in later centuries and across the seas to the Americas, India, the Far East, southern and interior Africa, Australia, and New Zealand. Overseas colonies were established, forming the enormous British Empire. Many of these colonies chose to retain trade and other ties to Britain when granted independence and are today part of the Commonwealth; because of these ties, however, the United Kingdom's entry into the European Union (EU) in 1973 was preceded by lengthy negotiations and dispute.
The Industrial Revolution began in the United Kingdom, which in the 19th century became the world's preeminent industrial and trading nation. In the 20th century, however, competition from more recently industrialized countries as well as the loss of its colonies (which had provided raw materials for Britain's industries and markets for their finished products) brought an economic decline. In the 1960s and 1970s severe labor disputes, unprecedented inflation, and declining exports contributed to a series of economic crises.
During the Industrial Revolution the country became rapidly urbanized, and today more than 70% of the total population is concentrated in cities occupying 10% of the total land area.
To protect the remaining countryside, national planning legislation has established ten national parks in the most scenic areas, including Dartmoor, the Lake District, the Pennines, the Snowdonia, the Pembrokeshire coast, North York Moors, Yorkshire Dales, Northumbria, Exmoor, and the Brecon Beacons. Other areas are also protected as Areas of Outstanding Natural Beauty.

LAND AND RESOURCES

Despite its small size, variety of scene is the main characteristic of the United Kingdom.

Lowland England

The largest area of flat plain occurs in The Fens, located on the east coast around The Wash. Before they were drained to produce a rich agricultural landscape similar to the polders in the Netherlands, The Fens were an area of marshland. Smaller flat areas are found along the River Humber estuary farther north on the east coast; along the Thames below London; and in Romney Marsh, in the southeastern county of Kent. Elsewhere, lowland England in the south and east is rolling country with a variety of landforms reflecting differences in underlying rock types. Especially prominent are the low hills and scarps developed on chalk rocks of Cretaceous age (135 million to 65 million years ago). They occur in the North and South Downs to the south of London, where the scarps face south and north, respectively, into The Weald; in Salisbury Plain, where the downs converge at their western end; and in the low hills that continue westward through the southern counties of Wiltshire and Dorset and swing eastward through the Isle of Wight. Northwestward from Salisbury Plain, the chalk hills form the prominent Chiltern Hills to the northwest of London; fall to lower elevations in the hills of East Anglia (Norfolk and Suffolk counties); and farther north form the Lincoln and York Wolds on either side of the Humber estuary.
To the west, separated from the chalk hills by an intervening lowland developed mainly on clays, rise a northeast-trending series of uplands developed on limestones of Jurassic age (190 million to 135 million years ago). They extend from the southern county of Dorset to the North York moors on England's northeast coast, and include the Cotswolds, which form a scarped edge overlooking the River Severn valley and rise to a high point of 314 m (1,031 ft) in Cleeve Cloud, near Cheltenham.
Also prominent in lowland England are the Mendip Hills, which rise to 326 m (1,068 ft) in Black Down, in the southwest near Bristol; Exmoor, which rises to 520 m (1,707 ft) in Dunkery Beacon farther west; Dartmoor, a granite-formed upland that rises to 621 m (2,039 ft) in High Willhays in the southwestern peninsula; and the Malvern Hills, which exceed 300 m (1,000 ft) between Gloucester and Worcester. Glacial deposits greatly modify topography and landforms north of an irregular line joining the River Thames and the Bristol Channel; often burying the underlying rock to considerable depths, the mantle of glacial deposits creates differing soil conditions as well as different drainage conditions from field to field.

Upland England

Uplands predominate in northern and western England. The most extensive uplands are the Pennines, which rise to 893 m (2,930 ft) in Cross Fell. Underlain mainly by limestones and grits of Carboniferous age (345 million to 280 million years ago), the Pennines are bordered on both sides by discontinuous coalfields, and the open moorlands of the Pennines contrast starkly with the sprawling industrial cities near the coal deposits. Numerous broad river valleys, known locally as dales, drain eastward across the mountains into the Vale of York, a north-south extension of lowland England that serves as the main route northward into Scotland. West of the Pennines are the Lancashire and Cheshire Plains and farther north England's scenic Lake District, which rises to 978 m (3,210 ft) in Scafell Pike, England's highest peak.