The island is dominated by a maritime climate with quite narrow temperature differences between seasons. Politically, the island is part of the United Kingdom of Great Britain and Northern Ireland, and constitutes most of its territory. Most of England, Scotland, and Wales are on the island. The term "Great Britain" often extends to include surrounding islands that form part of England, Scotland, and Wales, and is also sometimes loosely applied to the UK as a whole.
A single Kingdom of Great Britain resulted from the union of the Kingdom of England (which had already comprised the present-day countries of England and Wales) and the Kingdom of Scotland by the 1707 Acts of Union. More than a hundred years before, in 1603, King James VI, King of Scots, had inherited the throne of England, but it was not until 1707 that the two countries' parliaments agreed to form a political union. In 1801, Great Britain united with the neighbouring Kingdom of Ireland, forming the United Kingdom of Great Britain and Ireland, which was renamed the "United Kingdom of Great Britain and Northern Ireland" after the Irish Free State seceded in 1922.
The archipelago has been referred to by a single name for over 2000 years: the term 'British Isles' derives from terms used by classical geographers to describe this island group. By 50 BC Greek geographers were using equivalents of Prettanikē as a collective name for the British Isles. However, with the Roman conquest of Britain the Latin term Britannia was used for the island of Great Britain, and later Roman-occupied Britain south of Caledonia.
The earliest known name for Great Britain is Albion (Greek: Ἀλβιών) or insula Albionum, from either the Latin albus meaning "white" (referring to the white cliffs of Dover, the first view of Britain from the continent) or the "island of the Albiones", first mentioned in the Massaliote Periplus in the 6th century BC, and by Pytheas.
The oldest mention of terms related to Great Britain was by Aristotle (c. 384–322 BC), or possibly by Pseudo-Aristotle, in his text On the Universe, Vol. III. To quote his works, "There are two very large islands in it, called the British Isles, Albion and Ierne".