François Leclerc du Tremblay (4 November 1577 – 17 December 1638), also known as Père Joseph, was a French Capuchin friar, confidant and agent of Cardinal Richelieu. He was the original "éminence grise", or "grey eminence": a powerful advisor or decision-maker who operates secretly or unofficially.
François Leclerc du Tremblay, or commonly known as Father Joseph, was the leader of the harshly intolerant Catholic lay organization in France known as the Company of the Holy Sacrament. The Company were crucial to Cardinal Richelieu's efforts to strengthen France.
Father Joseph viewed the Ring of Fire and the Americans as the result of witchcraft. Richelieu had claimed that he was influenced too much by Father Joseph to support his claim. Rebecca Abrabanel met Father Joseph before meeting Richelieu. She regarded the Capucin monk as a harsh fanatic.
After the French Civil War, Joseph Tremblay was arrested by Gaston's regime. To conceal his identity, he was forced to wear an Iron Mask.