Some 10-12,000 years ago, near the tail end of the last ice age when sea levels were much lower, what we know as modern day Britain was just another oddly-shaped chunk of land connected to the European mainland. Some clans of hunter-gatherers stumbled onto this spit of land and by the time they realized the weather was always for shit and wasn't going to improve, the sea level had risen again, cutting off their retreat to mainland Europe. Modern day Brits are thankful for this because there's otherwise a good chance they'd have become French.
In the first recorded instance of early Brits keeping the now-famous "stiff upper lip", they accepted their lot and set about populating the island. The early seeds of discord were sown when everyone grew weary of trying to understand the utterances of a clan who spoke an unintelligible dialect completely devoid of vowels. This clan was banished to the far western part of the island and came to be known as the Welsh.
At about the same time, another clan known for being the most unruly of the new arrivals (and nearly as unintelligible as the Welsh) were sent off to the far north of the island. This clan became known as the Scots. They would later develop a beverage that would give rise to millions of pretentious assholes claiming to be experts on the topic.
These various clans inhabiting the island of Britain would - in no particular historical order - tangle with and ultimately boot the Roman empire, build Stonehenge, piss off the French, launch a series of crusades, advance modern western civilization as we know it, piss of the French again, spawn the United States, deliver a form of democratic government to the third world, be reinvented by the French, piss off the French yet again, and provide to the world a steady stream of pretty fucking good rock bands.
Hey...anyone who pisses off the French that much can't be all that bad.