Britain, better known nowadays as the UK of GB and Northern Ireland, comprises England, Scotland, Wales and Northern Ireland. The biggest island, GB, is divided into England, Scotland and Wales; whereas Northern Ireland shares the second largest island with the Republic of Ireland. In prehistory, these areas were visited by Old, Middle and New Stone Age nomads, some of whom later settled permanently. From about 600BC-AD1066, the islands experienced several settlements and invasions from peoples from mainland Europe such as Celtics, Belgic tribes, Romans, Germanic tribes, Scandinavians and Normans; whom over time collectively created a multi-ethnic British population with mixed identities and different origins.
The early invaders and settlers contributed to create gradually the separate nations of England, Wales, Scotland and Ireland between the 9th and the 12th centuries, where Scotland and England gained strong identities by the 10th century. There were several internal situations as well as external conflicts in their historical growth to nationhood. Some of these differences still exist between the four countries.
Later developments within the islands were influenced first by the expansionist, military aims of English Monarchs and second by a series of political unions. So, in the twelfth and thirteenth centuries, Ireland and Wales were annexed to England respectively. And in the seventeenth century, Scotland were joined dynastically England. In 1707, England, Scotland and Wales became unified as Great Britain, and in 1801 Ireland joined them. But in 1921, southern Ireland left the union to become the independent Republic of Ireland, while Northern Ireland remained part of UK.
The modern British state developed in an evolutionary and pragmatic manner. This process has been attributed to the supposed insular and conservative mentality of island peoples. However, the absence of any successful external military