Guy Fawkes, who was in the cellar of the parliament with the 36 barrels of gunpowder when the authorities stormed it in the early hours of November 5th, was caught, tortured and executed.
It's unclear if the conspirators would ever have been able to pull off their plan to blow up the Parliament even if they had not been betrayed - some people think the gunpowder they were planning to use was so old as to be useless. Since Guy Fawkes and his colleagues got caught before trying to ignite the powder, we'll never know for certain.
These days, Guy Fawkes Day is also known as Bonfire Night. The event is commemorated every year with fireworks and burning effigies of Guy Fawkes on a bonfire.