The story goes that on 5 November 1605, a man named Guy Fawkes (and his cronies) tried to blow up the House of Lords in an attempt to assassinate King James I. Fawkes had 36 barrels of gunpowder that would have surely done the job, but someone tipped off one of the Lords and the men were caught in the act. The people of England were apparently so happy that the King had not been killed, they lit bonfires in celebration. A few months later, the 'Observance of the 5th of November 1605' act was passed in Parliament and November 5th became an annual public holiday.
And what happened to Guy Fawkes? Eight members of the Gunpowder Plot were captured and eventually sentenced to be hanged, drawn and quartered. Ouch.
In modern Britain, Bonfire Night is often celebrated with fireworks instead of a bonfire (likely due to health and safety concerns). Some towns and villages will host a public bonfire (and sometimes they will burn a lifesize Guy Fawkes doll thingie) and you do still get the odd person thinking they can manage their own bonfire in their garden or something, but this is usually a pretty bad idea. It likely won't come as a surprise that the London Fire Brigade responded to a call for an out of control bonfire every 10 minutes on last year's bonfire night. Leave it to the experts folks.
Do your part to keep UK traditions alive - do a search here to see if there are any celebrations around you. Many will have taken place last weekend, but there are still some to come.
Oh and if you have pets, Bonfire Night (just like Forth of July) can be a scary time - keep them safe and happy!