was the plan successful?
No, it was a failed assassination attempt
Gunpowder Plot
 was a failed assassination attempt 
who tried to blow up what in 1605 Robert Catesby planned  to blow up the House of Lords during the State Opening of Parliament in 1605 what were the details of the plan? The first meeting between the five conspirators took place on 20 May 1604, probably at the Duck and Drake Inn, just off the Strand, Thomas Wintour's usual residence when staying in London. Catesby, Thomas Wintour, and John Wright were in attendance, joined by Guy Fawkes and Thomas Percy.
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Gunpowder Plot [SEP] Introduction
The Gunpowder Plot of 1605, in earlier centuries often called the Gunpowder Treason Plot or the Jesuit Treason, was a failed assassination attempt against King James I by a group of provincial English Catholics led by Robert Catesby. The plan was to blow up the House of Lords during the State Opening of Parliament on 5 November 1605, as the prelude to a popular revolt in the Midlands during which James's nine-year-old daughter, Elizabeth, was to be installed as the Catholic head of state. Catesby may have embarked on the scheme after hopes of securing greater religious tolerance under King James had faded, leaving many English Catholics disappointed.