why was the above assassination unsuccessful?
An anonymous letter sent to William Parker, Upon reading it, James immediately seized upon the word "blow" and felt that it hinted at "some strategem of fire and powder", perhaps an explosion exceeding in violence the one that killed his father
Gunpowder Plot
The plot was revealed to the authorities in an anonymous letter sent to William Parker, 4th Baron Monteagle, on 26 October 1605. 
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. was the plan successful? No, it was a failed assassination attempt who was the above mentioned planner? He was the leader of a group of English Catholics. can you name his famous relatives? Modern actor and producer Kit Harington what are his works as a producer? Harington developed, produced and starred in the BBC drama series "Gunpowder" (2017) based around the leading role of his ancestor Robert Catesby in the Gunpowder plot. who founded the label that hosted the above mentioned series? The BBC is established under a Royal Charter and operates under its Agreement with the Secretary of State for Digital, Culture, Media and Sport. when was it launched? 1932
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Gunpowder Plot [SEP] Introduction
His fellow plotters were John and Christopher Wright, Robert and Thomas Wintour, Thomas Percy, Guy Fawkes, Robert Keyes, Thomas Bates, John Grant, Ambrose Rookwood, Sir Everard Digby and Francis Tresham. Fawkes, who had 10 years of military experience fighting in the Spanish Netherlands in the failed suppression of the Dutch Revolt, was given charge of the explosives. The plot was revealed to the authorities in an anonymous letter sent to William Parker, 4th Baron Monteagle, on 26 October 1605. During a search of the House of Lords in the evening on 4 November 1605, Fawkes was discovered guarding 36 barrels of gunpowder—enough to reduce the House of Lords to rubble—and arrested.