In 1604, Guy Fawkes was recruited by Thomas Winter to join the Gunpowder conspiracy and came to London. Once Percy had rented the house next to the House of Lords and it was decided that Fawkes would pretend to be Percy's servant and live there. He adopted the false identity of John Johnson and was closely involved in business of digging a tunnel under the House of Lord and procuring gunpowder.
Finally, he was caught guarding the barrels of gunpowder.