United Kingdom
Prior to the Roman conquest, Britain was home to about 30 indigenous tribes. The largest were the Belgae, the Brigantes, the Silures and the Iceni. Historian Edward Gibbon believed that Spain, Gaul and Britain were populated by “the same hardy race of savages”, based on the similarity of their “manners and languages.” 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 Brittonic area mainly to what was to become Wales, Cornwall and, until the latter stages of the Anglo-Saxon settlement, the Hen Ogledd (northern England and parts of southern Scotland). 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 (with connections to the north-east of Ireland and traditionally supposed to have migrated from there in the 5th century) united with the Picts to create the Kingdom of Scotland in the 9th century.
In 1066, the Normans and their Breton allies invaded England from northern France. After conquering England, they seized large parts of Wales, conquered much of Ireland and were invited to settle in Scotland, bringing to each country feudalism on the Northern French model and Norman-French culture. The Anglo-Norman ruling class greatly influenced, but eventually assimilated with, each of the local cultures. Subsequent medieval English kings completed the conquest of Wales and made unsuccessful attempts to annex Scotland. Asserting its independence in the 1320 Declaration of Arbroath, Scotland maintained its independence thereafter, 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, while the Kings of Scots were in an alliance with the French during this period. Early modern Britain saw religious conflict resulting from the Reformation and the introduction of Protestant state churches in each country. Wales was fully incorporated into the Kingdom of England, and Ireland was constituted as a kingdom in personal union with the English crown. In what was to become Northern Ireland, the lands of the independent Catholic Gaelic nobility were confiscated and given to Protestant settlers from England and Scotland.
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, legal, and religious institutions.
In the mid-17th century, all three kingdoms were involved in a series of connected wars (including the English Civil War) which led to the temporary overthrow of the monarchy, with the execution of King Charles I, and the establishment of the short-lived unitary republic of the Commonwealth of England, Scotland and Ireland. During the 17th and 18th centuries, British sailors were involved in acts of piracy (privateering), attacking and stealing from ships off the coast of Europe and the Caribbean.
Although the monarchy was restored, the Interregnum (along with the Glorious Revolution of 1688 and the subsequent Bill of Rights 1689, and the Claim of Right Act 1689) ensured that, unlike much of the rest of Europe, royal absolutism would not prevail, and a professed Catholic could never accede to the throne. The British constitution would develop on the basis of constitutional monarchy and the parliamentary system. With the founding of the Royal Society in 1660, science was greatly encouraged. During this period, particularly in England, the development of naval power and the interest in voyages of discovery led to the acquisition and settlement of overseas colonies, particularly in North America and the Caribbean.