Guy Fawkes was a member of an English Roman Catholic revolutionary group, who had actually planned to carry out the Gun Powder Plot. This group was headed by Rober Catesby but Fawkes was the in charge of executing the plan. He was chosen because he had experience in military and explosives.
A number of factor contributed to Fawkes revolutionary thoughts. His childhood friends Thomas Morton, John and Christopher Wright and also John Pulleyn.
Another factor was his the influence of his step father. He was a Catholic Denis Bainbridge of Scotton. His family was known for their resistance against the authority of the Church of England. Due to his influence, Guy became a Catholic at the age of 16. He then, came to know about repression of Parliament on local Catholics. The murder of Margaret Clitherow has a lasting affect on him. She was murdered because she had harbored a Catholic priest at her home so she was crushed to death.
The final blow to it came around when their group realized that the Kingdom of Spain was fighting too many wars and was in complete debt to assist the Catholics of England. So they thought they had to do something themselves to finish the repression of King James and Parliament.