Thirty-six barrels of gunpowder were found with Guy Fawkes beneath Parliament in 1605.
The barrels were stored in a rented undercroft beneath the House of Lords. The conspirators intended the explosion to destroy the chamber during the State Opening of Parliament, killing King James I and the assembled politicians. Guy Fawkes was left in the cellar with the explosives and a slow match.
A search party inspected the undercroft during the night of 4–5 November. The discovery of 36 barrels made the danger appear enormous, although historians have debated how effective the stored gunpowder would have been after its long period in storage. Fawkes was arrested before he could light it.
Modern retellings sometimes use a rounded figure or focus only on “barrels of powder.” The specific historical figure recorded in accounts of the plot is 36. The discovery became the central event behind Bonfire Night’s fireworks and burning effigies.