Mary, Queen of Scots, sealed her final missive with an intricate spiral letterlock

Enlarge / 4 vector drawings present the five-slit spiral lock mechanism utilized by Mary, Queen of Scots; the back and front of a locked letter packet utilizing this technique; and an unfolded lock. Sections are numbered 1-20 to point out the completely different areas created by folding.

Unlocking Historical past Analysis Group

On the eve of her execution for treason in February 1587, Mary, Queen of Scots, penned a letter to King Henri III of France and secured it with a paper lock that featured an intricate spiral mechanism. So-called “letterlocking” was a standard apply to guard non-public letters from prying eyes, however this spiral lock is especially ingenious and delicate, in keeping with a brand new paper revealed within the Digital British Library Journal.

The authors are an interdisciplinary workforce of researchers working below the umbrella of the Unlocking Historical past Analysis Group. On this paper, they describe a dozen examples of a spiral lock in letters dated between 1568 and 1638, together with one from Mary’s former mother-in-law, Catherine de Medici, in addition to her arch-rival, Elizabeth I, who signed Mary’s loss of life warrant.

As we reported beforehand, co-author Jana Dambrogio, a conservator at MIT Libraries, coined the time period “letterlocking” after discovering such letters whereas a fellow on the Vatican Secret Archives in 2000. The Vatican letters dated again to the fifteenth and sixteenth centuries, they usually featured unusual slits and corners that had been sliced off. Dambrogio realized that the letters had initially been folded in an ingenious method, basically “locked” by inserting a slice of the paper right into a slit, then sealing it with wax. It could not have been attainable to open the letter with out ripping that slice of paper—proof that the letter had been tampered with.

Dambrogio has been learning the apply of letterlocking ever since, typically creating her personal fashions to showcase completely different methods, finally forming the Unlocking Historical past Analysis Group. The apply dates again to the thirteenth century—a minimum of in Western historical past—and there are numerous completely different folding and locking methods that emerged over the centuries. “It is not like folks may simply go to a store and purchase an envelope,” Dambrogio’s co-author from King’s Faculty London, Daniel Starza Smith, instructed Ars.


Queen Elizabeth I, Machiavelli, Galileo Galilei, and Marie Antoinette are among the many well-known personages recognized to have employed letterlocking for his or her correspondence. There are a whole bunch of letterlocking methods: for instance, “butterfly locks,” a easy triangular fold-and-tuck, and an ingenious technique often known as the “dagger-trap,” which includes a booby-trap disguised as one other, easier kind of letter lock. And naturally, there’s the intricate spiral lock that Mary, Queen of Scots, used for her ultimate missive, which includes an uncommon self-destruct characteristic.

Enlarge / The final letter written by Mary, Queen of Scots, on the eve of her execution. It was addressed to her former brother-in-law, Henri III, King of France.

Unlocking Historical past Analysis Group

Earlier this 12 months, Dambrogio’s workforce was in a position to make use of X-ray tomography to nearly “unlock” a letter written in 1697 by a person named Jacques Sennacque. Their evaluation revealed its contents for the primary time, proper all the way down to the watermark within the form of a chicken, as described in a paper revealed within the journal Nature Communications. That letter was a part of the Brienne Assortment, a group of two,600 “locked” letters—600 of which had by no means been opened—present in a Seventeenth-century trunk of undelivered letters preserved within the postal museum at The Hague, the Netherlands.

The unopened letters within the Brienne Assortment meant that rather more materials proof (crease marks and wax seals, as an illustration) a few given letter’s inner safety was preserved, particularly proof of tucks and layer order, which usually go away no materials hint. In contrast, the letters examined on this newest paper have all been opened, presenting a unique form of problem for the researchers of their ongoing quest to reverse-engineer the creation of letterlocks.

A excessive proportion of the fabric proof for the letterlocks is normally destroyed by opening the letter, and the spiral lock is designed to destroy not simply the lock, but additionally generally parts of the particular letter as an added safety measure, in keeping with the authors. Subsequent dealing with by students and conservationists may obscure proof of using a letterlock. Such gadgets are generally certain into letter books or saved after flattening and humidification, and the remnants of wax seals may be saved individually, discarded, or reattached incorrectly.