Guy Fawkes - There are quite a few people on the internet who have developed their own theories on Fawkes - but quite simply "It's because he tried to blow up the British Parliament because he didn't believe that England should break away from the Church of Rome. In other words, he was a Catholic who didn't like England being Protestant." in one of the most famous plots of the 1600's - still marked today with events such as Guy Fawkes day (Remember remember the fifth of November)
The Gunpowder Plot was about religion. England was a Protestant country, and the plotters were Catholic. The group wanted to return England to the Catholic faith. They thought they could do this by killing King James I and his ministers.