Quest for "Trevanion's Cipher"

The story of Sir John Trevanion's escape from Colchester Castle is quoted by many authors (including myself) as an example of a spectacular use of a concealment cipher. However, its authenticity does not seem to be established.

"Trevanion's Cipher"

The story goes like this.

At the time of the English Civil War, Sir John Trevanion was locked up in Colchester Castle in Essex (to the northeast of London). His fellow royalists Sir Charles Lucas and Sir George Lisle had just been executed and he was expecting the same fate. Then, the gaoler delivered him a letter. On the following evening, Sir John asked to be allowed to pass an hour of private devotion in the chapel. The request was granted but when the promised hour had expired, the prisoner was gone.

As it happened, the letter delivered at the last minute told Sir John a way to escape. The letter must have been examined so as not allow conveyance of such information but the message was cleverly hidden in apparently innocuous words from a friend consoling a doomed prisoner.

The letter is as follows:

Worthie Sir John, --Hope, that is ye beste comfort of ye afflicted, cannot much, I fear me, help you now. That I would saye to you, is this only: if ever I may be able to requite that I do owe you, stand not upon asking me. 'Tis not much that I can do: but what I can do, bee ye verie sure I wille. I knowe that, if dethe comes, if ordinary men fear it, it frights not you, accounting it for a high honour, to have such a rewarde of your loyalty. Pray yet that you may be spared this soe bitter, cup. I fear not that you will grudge any sufferings; only if bie submission you can turn them away, 'tis the part of a wise man. Tell me, an if you can, to do for you anythinge that you wolde have done. The general goes back on Wednesday. Restinge your servant to command. R.T.

Picking up each third letter after punctuation reveals the true message:



An attempt to check this episode against historical facts would immediately bring up some doubts. First, Colchester fell in 1648 but one known John Trevanion (Wikipedia) had died in 1643. Some versions of the story mention execution of Charles Lucas (Wikipedia) and George Lisle but historical records do not mention a Trevanion with these prisoners. According to Penny cyclopaedia of the Society, Vol. IX (Google), p.32 and Wikipedia, "Siege of Colchester", the other persons sentenced to death with Lucas and Lisle were Bernard Gascoigne and Colonel Farre and the former, being a foreigner, was reprieved and the latter escaped.

Secondary Sources

No modern author seems to quote a primary source of this episode. The authority in the field, David Kahn's The Codebreakers cites C. C. Bombaugh, Oddities and Curiosities, ed. Martin Gardner (reprinted New York: Dover Publications, inc. 1957). According to the Introduction of the 1961 edition in the possession of the present author, the chapters reprinted are from the third and last revision (in 1890) of Gleanings for the Curious (1874), Bombaugh's most popular book.

Trevanion's cipher is mentioned by none of the major works on cryptography by earlier English authors: John Falconer's Cryptomenysis Patefacta (1685) (see another article), John Davys' An Essay on the Art of Decyphering (1737) (see another article), Philip Thicknesse, A treatise on the art of decyphering and of writing in cypher with an harmonic alphabet (1772) (cf. an article in Japanese), and William Blair's 'Cipher' in Rees' Cyclopaedia (1807) (see another article).

A quick search on the web reveals that the same story is repeated by many publications during 1860s to the early 20th century. The earliest that could be found dates back to 1853.

1853 (UK): The National miscellany: A magazine of general literature, Volume 1, London, p.356 (Google)

1863 (UK): Once A Week: Volume 9, London, p.610 (21 November 1863) (Google)

1863 (US): Harper's Weekly, 19 December 1863, New York (quoted below). This issue can be found online at an American Civil War website but I could not locate the source.

1864 (NZ): Otago Witness, 26 March 1864, New Zealand (Papers Past) This cites "Once a Week" (above) as the source.

1866 (US): Albert J. Myer, A manual of signals: for the use of signal officers in the field, and for military and naval students, military schools, etc., New York, p.311 (Google) This cites its source as Harper's Weekly, December 19, 1863.

1869 (UK): S. Baring Gould, M.A., Curiosities of Olden Times, p.15 (Internet Archive)

1874 (US): Gleanings for the Curious from the Harvest Fields of Literature (the basis of Kahn's quotation mentioned above) (Google (1875), Internet Archive (1890))

1878 (UK): ULULA: The Manchester Grammar School Magazine (Google)

1908 (NZ): Star, 18 February 1908, New Zealand (PAPERSPAST)

1908 (NZ): New Zealand Tablet, 9 April 1908, New Zealand (PAPERSPAST)

1913 (US): The Century illustrated monthly magazine, Vol. 85 (Google, Internet Archive)

1925: M. E. Ohaver (ed.), "Solving Cipher Secrets", Flynn's, 21 February 1925 (

It seems most of the versions other than the one of 1853 seems to be textually identical. The 1853 source includes some names not mentioned by later sources and may be worth quoting.

Sir John Trevanion was a distinguished royalist officer in the Great Rebellion. He is sitting a prisoner in Colchester Castle, the night after the bloody murder of Sir Charles Lucas and Sir George Lisle. Darkness is closing in over the town. One or two rooks caw, as they sail past the battlements to their home in some Essex wood. Sir John is thinking of the two officers, whose blood cries for vengeance against Fairfax, and anticipating his own fate: for it is whispered that he also is to be made an example to deter men from loyalty.
The door creaks and opens, and the gaoler enters.
"Well, friend, any news?"
"None, that I know of," answers the Puritan, "except that we seek the Lord to-morrow after the crowning mercy of to-day."
"It will be a long time before you find Him by such bloody doings as this morning's, methinks. What is that paper?"
"A letter for you," replies the gaoler. "Truly godly master Bampfylde did make some difficulty about passing it: but as he deemed that there was no harm therein, after he and precious Master Tatham, the lecturer at Peter's, had read it over to their best judgment, he even bade me carry it to you."
"I am obliged to you," says Sir John. "Hold, here's a half Carolus for you. Some day I may chance to pay my debt to Master Bampfylde in a different manner."
The gaoler departs. The royalist, going close to the grated window, reads the letter.
[the rest omitted]

One known Bampfylde (Bampfield) (see another article) often carried secret letters to and from Charles I held in the Isle of Wight. About June-July 1648, Bampfield went to Holland but totallly lost his credit with the Duke of York, whom he helped escape from the Parliamentarians earlier this year. He returned to England in the latter part of 1648 but his connection with Colchester could not be confirmed. (Colonel Joseph Bampfield's Apology p.131, 129, Jock Haswell, James II p.39-40)

Archaeological Findings

Some years ago, the present author found a snippet of a seemingly relevant article on the episode on Google Books, which cannot be viewed now. According to private notes at hand, it was from Journal of the British Archaeological Association vol.28 (1922). It said "Local legends speak of a prisoner escaping from the castle during the period of the civil wars by making use of a communication conveyed to him in a cypher letter. The message read, 'Panel at east end of chapel slides', and in a recess of a wall of the crypt was discovered the remains of a narrow stairway. The passage is blocked with débris, and as a modern fixture at present prevents fuller ...." The 1922 excavation is recorded here, referring to pp.198-208 of the above volume and other publications.

(Notes added in December 2020) The article mentioned above turned out to be A. M. Jarmin (Councillor) (1922) "Recent Discoveries at Colchester Castle", Journal of the British Archaeological Association, 28:2, 198-208, DOI:10.1080/00681288.1922.11894501. The one paragraph relevant to Trevanion's story is as follows, which leaves the mystery unsolved.

There was one more discovery in the crypt which now forms the home of the priceless collection of local antiquities. Local legends speak of a prisoner escaping from the castle during the period of the civil wars by making use of a communication conveyed to him in a cypher letter. The message read, "Panel at east end of chapel slides," and in a recess of a wall of the crypt was discovered the remains of a narrow stairway. The passage is blocked with débris, and as a modern fixture at present prevents fuller explorations, the solution of the mystery must perforce be deferred.

(Notes added in May 2023) I received some details of the chapel of Colchester Castle from Paul Hodgetts. His father Michael Hodgetts, an acknowledged expert on priest holes, got interested in the Trevanion episode because it belongs to the period between the Gunpowder Plot and Charles II's escape after Worcester, when priest holes were not much in use. Michael, who retold the Trevanion story in his book, Secret Hiding Places (1989), had pointed out in an earlier academic publication that either the name or the date was wrong. His notes further provide information about the chapel:

.... The chapel was on the second floor of the keep, at the south-east corner. It has now been mostly destroyed but apparently had an arcade and ambulatory, like the chapel of St John in the White Tower, London. The projecting turret on the south of the apse contained a small side-chapel with an eastern apse. The walls of the sub-chapel below are 15 ft thick (Royal Commission on Historic Monuments: North-East Essex (1922), pp. 52-54) so there would have been ample room within the walls of the chapel itself for a mural passage or staircase - presumably part of the Norman or medieval construction which had been covered up and turned to other uses.

Because the chapel was on the second floor, the crypt where the stairway was found in the excavation would have been three levels below the chapel, as Paul points out (remember that, in British English, the first floor is above the ground floor). Still, the expert's view that there would have been ample room within the walls makes us hope that the story is more than just a legend.

According to Gardiner, History of the Great Civil War, 1642-1649, p.199, n.1 (Internet Archive), there were many dubious "catchpenny productions" at the time, allegedly derived from escaped townsmen. While Trevanion's episode may be one of such stories, the cipher seems too elaborate to be a mere sham. A reader who could locate a more authentic source of Trevanion's episode is kindly asked to contact the present author.

Peripheral Information

A P Baggs et al., 'Castle', in A History of the County of Essex: Volume 9, the Borough of Colchester (1994), pp. 241-248 (British History Online) describes the history of the Colchester Castle and that the castle was sold to the parliamentarian Sir John Lenthall, but does not mention the episode.

There is a Calendar of prisoners in Colchester castle goal (1650) in Essex Record Office (catalogue information), but I do not know whether it contains relevant information.

©2012 S.Tomokiyo
First posted on 13 September 2012. Last modified on 30 May 2023.
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