As I was listening to the Revolutions podcast I was struck by how little these plots accomplished. I would like to stick to early 17th century England, but would be curious if any secret cabals managed to succeed on the continent as well during this time period.
The Glorious Revolution of 1688 originated in a conspiracy between disaffected Whigs, Tories and bishops who were unhappy at James II's policies and who therefore invited William of Orange, ruler of the Dutch Republic, to invade England. They claimed that 19 out of 20 people in England wanted a change in policies but they needed "a protection to countenance their rising as would secure them from being destroyed before they could get to be in a posture to defend themselves". They wanted William and his army to provide this protection.
The 'Immortal Seven' on 20 June 1688 sent William an invitation to invade England. The Seven comprised of the Earl of Devonshire, Henry Compton (Bishop of London), Lord Lumley, the Earl of Danby, Edward Russell, Henry Sidney, and the Earl of Shrewsbury. They signed it by cipher as a way of insuring themselves if it was captured. The number seven had a biblical significance (Revelation 1:20: "The mystery of the seven stars which thou sawest in my right hand, and the seven golden candlesticks. The seven stars are the angels of the seven churches: and the seven candlesticks which thou sawest are the seven churches"). They were rather disparate, being both Whigs and Tories, but James' policies united them in resistance.