I have one in my head, but we never bothered with one, we were just focusing on the balance and basics
Here's my unofficial explanation:
In the bleak dystopian future of the year 2000, when Margret Thatcher never stepped down from government, continuing to oppress the working class and keeping the punk movement alive. Eventually, the country, crippled by austerity and overbearing taxes, descended into anarchy. nobody quite knows how it happened but when the dust settled, the country had split into different areas, with Scotland gaining Independence and sealing their borders, and these city states and areas manage to start enforcing their own laws and pacifying the surrounding regions. There's still a lot of anarchy out there though, and other factions to be dealt with. Are you a bad enough dude to re-unite whats left of England?
This is my explanation of events, at the very least, as for david, who knows, we were far more busy removing bugs and trying to boost Bristol to discuss back story all that much