The Gunpowder Plot was intended to kill James I, the monarch commemorated indirectly by Bonfire Night history.
James was king of Scotland as James VI and became king of England and Ireland in 1603, after Elizabeth I died. His accession created the political setting for the plot, because some English Catholics hoped a new monarch might end discriminatory laws against them.
The conspirators planned to destroy the House of Lords during the state opening of Parliament on 5 November 1605. They also intended to seize Princess Elizabeth and establish a Catholic succession. The plan failed when Guy Fawkes was discovered with gunpowder beneath Parliament.
A common mix-up is confusing James I with James II. James II became king much later, in 1685, and was not the monarch targeted by the Gunpowder Plot.