Henry Knyvet was an English nobleman known for his role during the late 16th century. He was a member of the Knyvet family, which held significant influence in England. Knyvet is most recognized for his involvement in the Gunpowder Plot of 1605, a failed conspiracy aimed at assassinating King James I and blowing up the House of Lords. Knyvet's actions during the plot led to his prominence in history. He was responsible for discovering the conspirators' plan and subsequently arresting Guy Fawkes, one of the key figures in the plot. His quick actions contributed to the foiling of the assassination attempt and the preservation of the monarchy.