Ciphered EuropeThird dossier · Danish diplomatic correspondence
Copenhagen, 1675: the price of Danish neutrality
In the spring of 1675 Denmark speaks with two voices. At The Hague its envoy promises the allies to go to war with Sweden. In Paris, the same register of ciphered dispatches negotiates with Louis XIV what Danish neutrality would cost. Read with a key found in the Rigsarkivet, the ciphered passages show this double game from the inside, week by week.
“Everything suggests that His Majesty will not need to look for pretexts to do what France wishes: the allies’ own conduct will provide plausible enough ones.”
Copenhagen to Meyercrone, Paris, 13 April 1675 (ciphered passage, paraphrased from the French).
Winter 1675: Sweden enters Brandenburg
Since 1672 Louis XIV has been at war with the Dutch Republic, Spain and the Emperor. At the end of December 1674 his Swedish ally sent an army into Brandenburg to force the Great Elector out of the coalition. Christian V’s Denmark, Sweden’s neighbour and rival, is courted by both sides: the allies want it to attack Sweden; France wants it to stay quiet. Danish policy is then in the hands of the Grand Chancellor, Peder Schumacher, Count Griffenfeld.
The German Chancery, which handles foreign affairs, copies its dispatches every week into a register kept by the secretary Conrad Biermann, leaving the sensitive passages in cipher. Two posts share the same key: Just Høeg, envoy at The Hague, and Henning Meyercrone, envoy to Louis XIV.
At The Hague: war against Sweden
The dispatches to Høeg speak the allies’ language. On 13 February 1675 Copenhagen argues that Sweden does not raise such forces without a design: it wants to bring down the Dutch, the main obstacle to its mastery of the Baltic coasts and trade. The only remedy would be to attack it “by sea and by land” while England cannot help it. Yet the same letter admits that the Swedish ambassador finds “well-disposed minds” among several Danish ministers.
In Paris: the price of neutrality
The dispatches to Meyercrone tell of another negotiation, conducted in Copenhagen by Griffenfeld with the French ambassador, Terlon, and relayed in Paris to the minister Pomponne. The sums appear only in the ciphered passages:
- 13 April: Terlon announces that Louis XIV is cutting his offer: 600,000 écus over two years instead of three. Griffenfeld replies that by following France, Denmark would lose the allies’ subsidies; Paris must make up for them, and keep paying after the peace.
- 22 May: 200,000 écus a year for three years is not enough; Denmark must not be treated worse than Sweden was before it went to war.
- 1 June: Terlon, on new orders, offers 300,000 écus a year for three years.
- 11 June: a paper containing a “provisional engagement” between the King of Denmark and Louis XIV is handed to Terlon, pending a formal treaty.
A marriage to please Louis XIV
On 5 June Copenhagen tells Meyercrone that it accepts Charles XI of Sweden’s proposal for Princess Ulrika Eleonora, Christian V’s sister. The consent is to be presented in Paris as a token of friendship towards Louis XIV, who wanted the match. On 8 June the letter goes further: the agreement made by the Danish envoys with the allies at The Hague was concluded “against the intention and even the orders” of the king. Copenhagen hopes the Swedish marriage will lead the allies to suspend their subsidies, which would give it “a legitimate reason” to leave them.
What these letters tell us
Historians know of Griffenfeld’s talks with France, notably from French sources. These dispatches give the Danish side, written day by day for Denmark’s own diplomats. They show three things:
- the ciphered bargaining over subsidies, from 600,000 écus over two years to 300,000 écus a year over three, with a demand for compensation for the lost allied subsidies;
- a written engagement handed to France on 11 June 1675, when the Danish envoys had already committed themselves at The Hague;
- the Swedish marriage used as a tool: to please Louis XIV and to provoke the break with the allies.
Events overturned these calculations. On 28 June 1675 the Swedish army was defeated by the Great Elector at Fehrbellin; in July Christian V forced the Duke of Holstein-Gottorp to give up his sovereignty and his Swedish alliance, which the letter of 21 June had already named as the only possible trigger; in September Denmark declared war on Sweden. This was the start of the Scanian War. Griffenfeld was arrested in March 1676, sentenced to death, then pardoned and imprisoned for life. Ulrika Eleonora married Charles XI only in 1680, after the peace.
The cipher
It is a French nomenclator. Each letter has three equivalents, two symbols and a number from 1 to 24; syllables run from 312 (“ba”) to 692, ordered by consonant; codes stand for persons and countries (111 Pomponne, 112 Terlon, 212 France, 216 Sweden). The key has no title: it is a sheet in the Chancery’s “Chiffer” volume, which we matched to the dispatches. The 26 letters from February to June are read in full, 97.6 to 100% of the cipher groups depending on the letter. The complete transcriptions, letter by letter, are on the Documents page.
What remains uncertain
- These are the register copies, not the originals sent; a copying error remains possible, especially with the sign “9”, which the copyist uses for several letters.
- A few isolated codes are unresolved (flagged in the entries); none affects the sums quoted here.
- We have not compared these letters with Terlon’s dispatches in the French archives. The modern paraphrases are ours.
References
Rigsarkivet (Copenhagen), Tyske Kancelli, Udenrigske Afdeling, “Conrad Biermanns kopibog over udgående skrivelser til danske ministre i udlandet”, 1675. Arkivalieronline ↗
Rigsarkivet, Tyske Kancelli, “Chiffer” 1670–1709, image 55. Arkivalieronline ↗
Daniel Bourdeau, catalogue of attempted and unread ciphers (cyphersolver repository), no. 465 “Conrad Biermann’s copybook”.
Entries “Copenhagen to Just Høeg” and “Copenhagen to Henning Meyercrone” on the Documents page, with the passages, method and credits.