What is the main explosive in the Gunpowder Plot's name?

The main explosive named in the Gunpowder Plot was gunpowder.

The plotters planned to place large quantities of gunpowder beneath the House of Lords and ignite it during the State Opening of Parliament on 5 November 1605. Their aim was to kill King James I, destroy the Protestant political leadership and trigger a Catholic uprising.

Guy Fawkes was assigned to guard the explosives and light the fuse. When authorities searched the undercroft after an anonymous warning reached William Parker, 4th Baron Monteagle, they found Fawkes with a slow match and 36 barrels of gunpowder hidden under firewood and coal.

The other options belong to different periods or contexts. Dynamite was invented centuries later, nitroglycerin was not the plot’s material, and Greek fire was a much older Byzantine incendiary weapon. The name directly identifies the substance central to the conspiracy.