The film adopts extensive imagery from the 1605 Gunpowder Plot, in which a group of Catholic conspirators plotted to destroy the Houses of Parliament in order to spark a revolution in England. The film was originally scheduled for release on the weekend of 5 November 2005, the Plot's 400th anniversary, with the tag line "Remember, remember the 5th of November", taken from a traditional British rhyme memorialising the event. However, the marketing angle lost much of its value when the release date was pushed back to 17 March 2006. Many have speculated that the delay was caused by the London tube bombing on the 7 July and the failed 21 July bombing. The filmmakers have denied this, saying that the delays were due to the need for more time to finish the visual effects production. "V for Vendetta" had its first major premiere on 11 December 2005, at Butt-Numb-A-Thon, followed by a premiere on 13 February 2006 at the Berlin Film Festival. It opened for general release on 17 March 2006 in 3,365 cinemas in the United States, the United Kingdom and six other countries.