The Gunpowder Plot was a to blow up the English Parliament and King James I on November 5, 1605, the day set for the king to open Parliament. It was intended to be the beginning of a great uprising of English Catholics, who were distressed by the increased severity of penal laws against the practice of their religion. The conspirators, who began plotting early in 1604, expanded their number to a point where secrecy was impossible. They included Robert Catesby, John Wright, and Thomas Winter, the originators, Christopher Wright, Robert Winter, Robert Keyes, Guy Fawkes, a soldier who had been serving in Flanders, Thomas Percy, John Grant, Sir Everard Digby, Francis Tresham, Ambrose Rookwood, and Thomas Bates. Percy hired a under the House of Lords, in which 36 barrels of gunpowder, overlaid with iron bars and firewood, were secretly stored. The conspiracy was brought to light through a mysterious letter received by Lord Monteagle, a brother-in-law of Tresham, on Oct. 26, urging him not to attend Parliament on the opening day. The first earl of Salisbury and others, to whom the plot was made known, took steps leading to the discovery of the materials and the arrest of Fawkes as he