An attempt on the part of a conspiracy to blow up the Parliament of England on Nov. 5, 1605, on the day of the opening, when it was expected the King, Lords, and Commons would be all assembled; the conspirators were a small section of Roman Catholics dissatisfied with King James's government, and were headed by Robert Catesby, the contriver of the plot; the plot was discovered, and Guy Fawkes was arrested as he was proceeding to carry it into execution, while the rest, who fled, were pursued, taken prisoners, and the chief of them put to death.