Great Britain is an island in the North Atlantic, just off the coast of Europe. The largest island in the archipelago called the British Isles, the word "Great" sadly refers to its size and not to any other quality. The French called it "Grande Bretagne" in order to distinguish it from "Bretagne" or Brittany - which is either uncharacteristically generous of the French or indicates a more characteristic lack of a sense of irony.
There is evidence of human life in Great Britain as early as 500,000 years BCE, and evidence of modern human ancestors approximately 30,000 years ago.
The first documented peoples of Britain known about were around in the Iron Age, around 800 years BCE, and referred to collectively as "Britons". Following the Roman occupation of Britain which started in 43CE and ended at the beginning of the 5th century, the peoples of Great Britain suffered invasions in the north from Irish Gaelic tribes, eventually forming the Kingdom of Scotland in the 9th century, and in the south east from assorted Angles, Jutes and Saxons, who are today referred to as Anglo-Saxons, credited with forming the Kingdom of England in the 10th century. Modern-day Wales developed its own identity following the withdrawal of the Romans from Britain and is today considered a modern Celtic nation, along with Scotland.
The countries of England, Wales and Scotland are located on the island. The southern two-thirds of the island is taken up by England, while the west midlands area belongs to Wales and the north of the island comprises Scotland. England's status as the largest country on the island has led some to the incorrect conclusion that "England" can be used to refer to the island as a whole. The name "Great Britain" is also sometimes used as a synonym for the political entity the United Kingdom, with or without the intention of omitting Northern Ireland from the Union. Although this is acceptable in casual usage, it is technically incorrect.
It is generally considered a fact that the only "great" thing Great Britain ever did was invent every popular sport in the civilized world, including football, golf, rounders, croquet, rugby and cricket. The British girl's game of rounders was, of course, converted into a mildly popular American sport known as "baseball".
The British schoolboy's game of rugby - in which almost no protective clothing is worn - was also converted by the Americans into their own variation known as American football (or just "football" as they call it in America) which also has a mild following. Rugby league is probably the real sport that is closest to this variant, which mostly consists of men overdressed in protective padding running into each other for ten to twenty seconds at a time, and then taking a thirty second breather whilst deciding where to run into each other next.
There are a number of possible ways to refer to people who are citizens of the United Kingdom of Great Britain and Northern Ireland.
One way is to use the adjective "British", as in "a British person" or a British product. Although this is a relatively neutral term to which the majority would not object it has a couple of problems. One is that although the majority would not object - some would. It is also a bit long winded. Alternatively you can say, "He's British", "She's British", "They're British".
Although newspapers sometimes use this word as in, "Three Britons Hurt in Exploding Moose Shock", the word "Briton" is rarely used in informal conversation. Indeed, when used in conversation most people would think of the "Ancient Britons" - the pre-Roman inhabitants of the present-day British islands.
This shortened form of the word is used and accepted by many - but not all - of the inhabitants of the islands. For various reasons some people do not seem to like the title. For example, as can be seen from the full name of the kingdom, it also includes the inhabitants of Northern Ireland. As a proportion of the citizens of this part, and indeed most parts, of the world are anti-British and the region has a special status, many (perhaps most) inhabitants would prefer to be called something else.
This term was coined by American sailors to refer to British sailors when they discovered that they used to drink lime juice in order to combat scurvy. It is generally not appreciated by citizens of the United Kingdom, especially in the common construction "Limey bastard".
Also shortened to "Pom", is a term used primarily in Australia, New Zealand, and South Africa to denote anyone of British nationality. It is (apparently) considered offensive, particularly in the common construction "Pommy bastard". It may have something to do with pomegranates.
This term has been proposed as a possible solution but it suffers from a number of shortcomings. It is almost unpronounceable, unknown internationally and neither used nor accepted by any significant population in the UK.
 Other random terms
Another obvious solution would be to call inhabitants according to their country/principality. It is, however, regrettable that most of the "local" names would run into some national or international problem.
There is increasing fragmentation of the UK. Wales has its own Assembly, while Scotland and Northern Ireland have Parliaments. The resulting nationalism has led to the rejection of the word Brit by much of the population. This "devolution" of Wales and Scotland did spark a trend of fairly serious suggestions for other parts of England to devolve power away from the London based parliament of the UK. This would lead to places like Cornwall and Northumberland essentially having their own parliament.. whatever next.
- The name Welsh would mean little to much of the world's people and the nationals of the principality are often lumped in with the English - to their great and justified annoyance.
- The name Northern Irish results in their being joined with Eire (Ireland). For some this would be desired but others would detest the idea. Although one occasionally hears the word Ulsterman being used to refer to a Northern Irishman, this is not actually appropriate as of the nine counties of the Province of Ulster three , Cavan (An Cabhán), Donegal (Dún na nGall) and Monaghan (Muineachán) form part of the Republic of Ireland.
- The name Scottish is the exception: most Scots prefer this reference but occasionally they too are referred to as English. Wars have been waged over lesser insults.
- The name English is frequently used by both foreigners and some English people to refer to the nationality of the whole country. Many English people find this a convenient solution but some regions of the country are starting to exhibit a regionalism verging on nationalism: Yorkshire; Cornwall; Northumberland and many others will tell you with pride that they are first and foremost Yorkshiremen (Cornishmen; Northumbrian), secondly English and so on. Others consider themselves foremost Cornish (etc) and then British. This is partly due to the fact that Cornwall was a later addition to England than the rest, being populated primarily by Celtic Britons who spoke their own language (Cornish).
 If you're looking for a fight
Ask an Irishman, "If England, Scotland and Wales are on Great Britain, does that mean Ireland is on Not-So-Great Britain?"