Henrietta Anne, Duchess of Orléans, and the Secret Treaty of Dover (1670)
Henrietta Anne (1644-1670), Duchess of Orléans and sister to King Charles II, was a key negotiator of an important diplomatic agreement between England and France. In 1670, Charles II and Louis XIV of France signed the Secret Treaty of Dover. Kept hidden from the public, it included Charles’s promise to publicly convert to Catholicism (which never happened) in exchange for vast sums of money, as well as a mutual alliance against the Dutch Republic.
The British Library holds a rich volume of papers relating to the Treaty which demonstrates Henrietta’s significant role and is largely written in French.
Henrietta had a brief but extraordinary life. Born in Exeter in 1644, she was quickly whisked away to France because of the English Civil War and raised at the French court. At sixteen, she married Phillippe, Duke of Orléans and brother of Louis XIV. She was highly educated and intelligent, but was embarrassed by her written English and wrote almost exclusively in French.
Title page of a flattering portrait of Henrietta, by Jean Puget de la Serre (1661). Add MS 33752, f. 3.
In 1669, Charles II wrote a top-secret letter to Louis about the treaty, entrusting its delivery to Henrietta: ‘desireing that this matter might passe through your handes as the person in the world I have most confidence in.’ Charles even sent Henrietta a cipher, so that their correspondence would be totally confidential.
Henrietta was politically invaluable: both exceptionally close with Charles and trusted enough by Louis that he met her almost every day in early 1670 to discuss the negotiations. She provided the link between the two monarchs that allowed Louis to address Charles as ‘monsieur mon frère’ in his letters.
Henrietta’s long letter to Charles II, 1669. Add MS 65138, f. 47.
Unfortunately, many of Henrietta’s letters were destroyed after her death. One of the most striking surviving documents is her letter to Charles about this ‘grande affaire.’ Henrietta, who was Catholic, refers to Charles’s conversion as ‘le desin de la R’ (‘the design about R’), with R standing for ‘religion.’ She advises Charles at length on finances, the prospect of war in Holland, and Louis’s motives. She even suggests that Charles conceal their scheme from the Pope, since he might die before the planned conversion!
After several pages of confident political discussion, Henrietta signs off with a show of modesty, writing that she only dares to meddle in questions above her station because of her great love for her brother.
A visit to Charles by Henrietta was the cover story for the final stage of the treaty’s formation, and she was personally charged with carrying the French copy back to Louis.
Final protocol of the Treaty, featuring the seals and signatures of Charles II’s principal advisors. Add MS 65138, f. 91v.
Tragically, Henrietta died just months later at the age of 26. One first-hand account states that she drank a glass of chicory water, a medicinal drink, before collapsing in agony (Stowe MS 191, f. 22). Another account ungenerously insists on her depraved, sinful life, claiming she was poisoned and spent her final moments repenting (Kings MS 140, f. 107).
What we can be sure of is her affection for Charles. She addresses her letter to him uncharacteristically in English: ‘For the King.’
‘For the King’: a rare example of Henrietta writing in English in her letter to Charles. Add MS 65138, f. 51v.
PhD candidate at the University of Cambridge and PhD placement student in Modern Archives and Manuscripts
Keith Feiling, ‘Henrietta Stuart, Duchess of Orleans, and the Origins of the Treaty of Dover’, The English Historical Review, Vol. 47, No. 188 (Oct., 1932), pp. 642-645.
Cyril Hughes Hartmann, Charles II and Madame (London, 1934).