Today, the British Isles contain two sovereign states: the Republic of Ireland and the United Kingdom. There are also three Crown dependencies: Guernsey, Jersey and the Isle of Man. The United Kingdom comprises England, Northern Ireland, Scotland, and Wales, each country having its own history, with all but Northern Ireland having been independent states at one point. The history of the formation of the United Kingdom is very complex.

The British monarch was head of state of all of the countries of the British Isles from the Union of the Crowns in 1603 until the enactment of the Republic of Ireland Act in 1949, although the term "British Isles" was not used in 1603. Additionally, since the independence of most of Ireland, historians of the region often avoid the term British Isles due to the complexity of relations between the peoples of the archipelago

British people say: "Other countries have a climate, in England we have weather."

The weather in Britain changes very quickly. One day may be fine and the next day may be wet. The morning may be warm and the evening may be cool. Therefore it is natural for the people to use the comparison "as changeable as the weather" of a person who often changes his mood or opinion about something. The weather is the favourite topic of conversation in Britain. When two Englishmen are introduced to each other, if they can't think of any thing else to talk about, they talk about weather. When two people meet in the street they will often say something about weather as they pass, just to show their friendliness.