The iconic version of the Guy Fawkes mask owes its popularity to the graphic novel and film V for Vendetta, which centers on a vigilante's efforts to destroy an authoritarian government in a dystopian future United Kingdom.
Although he didn't predict the mask's role in popular protest, David Lloyd, the artist who illustrated the comic, told The New York Times, "It's a great symbol of protest for anyone who sees tyranny."
Guy Fawkes Night originates from the Gunpowder Plot of 1605, a failed conspiracy by a group of provincial English Catholics to assassinate the Protestant King James I of England and replace him with a Catholic head of state. In the immediate aftermath of the 5 November arrest of Guy Fawkes, caught guarding a cache of explosives placed beneath the House of Lords, James's Council allowed the public to celebrate the king's survival with bonfires, so long as they were "without any danger or disorder".
This made 1605 the first year the plot's failure was celebrated.
The following January, days before the surviving conspirators were executed, Parliament passed the Observance of 5th November Act, commonly known as the "Thanksgiving Act". It was proposed by a Puritan Member of Parliament, Edward Montagu, who suggested that the king's apparent deliverance by divine intervention deserved some measure of official recognition, and kept 5 November free as a day of thanksgiving while in theory making attendance at Church mandatory.
A new form of service was also added to the Church of England's Book of Common Prayer, for use on that date.
Guy Fawkes Night - Wikipedia