Robert Catesby

 Robert Catesby was the mastermind behind the Gunpowder Plot of November 1605. (MA: The Plotters, VG: The Gunpowder Plot)

In 1601, Catesby joined the Earl of Essex in rebellion against Elizabeth I. As a result of this, he was imprisoned, fined 4,000 marks and lost his estate. As part of his plot to blow up Parliament and kill James I inside, and enstate Princess Elizabeth as the Catholic Queen, in 1605 he asked the Eleventh Doctor, who was secretly stopping this plot, to give him a sleeping potion. (VG: The Gunpowder Plot)