Bonfire Night is celebrated throughout the UK on the 5th of November. The date marks the aniversary of an attempt to blow up the Houses of Parliament in 1605 by Guy Fawkes and a group of co-conspiritors.
Guy Fawkes and his group were Catholic extremists who were unhappy with the way Catholics were treated by the (Protestant) state and wanted to return the country to the Catholic faith. They hatched a plan to blow up parliament, killing everyone in gevernment and the King (James 1st).
The plot was uncovered because one of the conspirators sent a letter to a friend in the Houses of Parliament warning him to stay away from the House on the day the attack was supposed to take place. The letter was intercepted and handed to the king.
Meanwhile, Guy Fawkes and friends, having formulated their plan, known as the 'Gunpowder Plot', had rolled 36 barrels of gunpowder into the cellars of the Houses of Parliament, and were waiting for the king to arrive when guards broke in and arrested them. They were tortured and executed.
The government of the time used the whole event as a bit of a propoganda tool to help justify severe anti-Catholic legislation and as justification for hunting down Jesuit priests throughout the UK. Bonfire night was introduced to mark the anniversary of the failed coup. It is worth noting that originaly an effigy of the Pope was burned and it was not until two centuries later that people switched to burning effigies of Guy Fawkes instead.
The extent of the celebrations and the size of the bonfire varies from one community to the next. Lewes, in the South East of England, is famous for its Bonfire Night festivities and consistently attracts thousands of people each year to participate. Nowadays bonfire night is generally considered a bit of a quirky tradition, and the religious and political aspects are largely ignored.
For those who want to firn out more, this site contains a lot of information on the plot itself and the politics of the time.