The Gunpowder plot was conceived by a certain Robert Catesby from Warwickshire. Catesby was a Catholic whose plan was to blow up Parliament during its opening ceremony on 5th November 1605, when the king would be present in the Palace of Westminster. With James I dead, Catesby would organize a Catholic uprising in the Midlands, capture either the young Prince Charles or Princess Elizabeth or both, and place one of them on the throne.
Catesby gathered together a group of Catholic fanatics, one of whom was Guy Fawlkes from Yorkshire. Fawlkes had been a captain in the Catholic Spanish army fighting against the Protestant Netherlanders. They rented the house next door to the Palace of Westminster and knocked down the wall adjoining the two cellars. There they placed 20 barrels of gunpowder, with iron bars on top, to ensure as much damage as possible from the blast. They covered their explosives with firewood and coal. Guy Fawlkes, using the name John Johnson, was in charge of looking after the explosives until the opening of Parliament.
The Gunpowder Plot never reached its conclusion. One of Catesby's group wrote a letter to his Catholic brother-in-law, Lord Monteagle, suggesting that he should not attend the opening. Lord Monteagle told Lord Salisbury about this letter, and Lord Salisbury, in turn, informed the king. Search parties were sent into the cellar and Guy Fawlkes was arrested. Even to this day, the cellars of the Palace of Westminster are searched before every opening of Parliament, and effigies of Guy Fawlkes are burnt on bonfires all around Great Britain on 5th November, or Bonfire Night, each year.