The so-called Atterbury Plot aimed to replace the Hanoverian King George I with the Stuart Pretender. Francis Atterbury, Bishop of Rochester, was arrested in August 1722 and by the proceedings in 1723 deprived of the spiritual dignities and banished for life.
Devoted High Churchman as he was, succession of George I of Hanover to the British throne in 1714 seemed to Atterbury prejudicious to the true interest of church. In the spring of 1716, he first responded to approaches from the Jacobites. Convinced that nothing could be attained without an armed invasion by a foreign power, he always counselled caution when he took part in discussions with the Jacobite agent George Kelly in the aftermath of the burst of South Sea Bubble. While in November 1721 he agreed to proposals by Jacobite agents of an armed landing in England, in several months he was frustrated with incompetent fellow conspirators and entirely broke off from them, possibly affected by the illness and death of his wife in April 1722. However, Sir Robert Walpole got wind of the plot and Atterbury was betrayed by the Earl of Mar, the Pretender's secretary of state. While Mar's evidence had to be kept secret, intercepted letters in cipher written by George Kelly, Mar's agent, were used against Atterbury. Atterbury was arrested in August 1722 and committed to the Tower of London. (Oxford DNB)
In January 1723, a committee of the House of Commons was set up to investigate the case, which essentially traced the work of Walpole and his colleagues in the preceding months to collect incriminating evidence against the Bishop. A report of the committee came out on 1 March 1723. (Oxford DNB)
The main evidence used against Atterbury was three letters (D.10, D.11, D.12 on p.247 ff.) partly in cipher dated 20 April 1722 (hereinafter, designations such as "D.10", "C.51", "F.11" etc. refer to the Appendix of the Report of the Committee of the House of Commons):
D.10: T. Jones to Chivers [General Dillon (Wikipedia)] (24 words (or parts thereof) were in cipher out of some 330 words; in the postscript, 45 out of some 110 words were in cipher (Davys p.37))
D.11: T. Illington to Musgrave [Earl of Mar (Wikipedia)] (69 out of some 250 words were in cipher)
D.12: 1378 to Jackson [the Pretender] (114 out of some 430 words were in cipher)
While these were written in George Kelly's hand, the code names "Jones", "Illington", and "1378" were all considered to refer to Atterbury, who dictated the letter.
The beginning of the letter to Musgrave is as follows.
A supplement (F.11 on p.303 of Report), in George Kelly's handwriting, to this cipher was found among the papers of Dennis Kelly. (Report, p.124; State Trials p.362) That this supplement, found in July, agreed with the key obtained through deciphering was considered to support the truth of the deciphering. (State Trials p.386)
The supplement cipher (F.11) contains fictitious names for twenty-three names ("Edmuns" and "Eagle" for Mr. Pendernis; "Gainer" and "Gifford" for General Trelawney; "Henderson" and "Hamden" for Sir William Courtney; etc.). It also includes numerical codes as follows. (Entries in bold are not in the supplement but taken from the specimen above to show the consistency of the deciphered code numbers agree with the supplement.)
272 Crawford Mr.1)
718, 719 I
806 Kennedy Frank2)
888, 889 Law John3)
890, 891 Law William4)
960, 961 me
1193 O Brien John5)
1570 Sutton Sir Robert6)
1571 Stanhope Col.7)
1572 Schaub Mr.8)
1) cf. A.7, A.9, A.31, F.1|
2) Francis Kennedy, a courtier in the Jacobite court
3) John Law (Wikipedia)
4) William Law (Wikipedia)
5) John O'Brien (?Wikipedia)
6) Sir Robert Sutton (Wikipedia, ambassador in France 1720-1721)
7) Colonel Stanhope (Wikipedia)
8) Luke Schaub (French Wikipedia, ambassador in France succeeding Sutton)
The House of Commons considered the Report on 8 March and passed a resolution that there was a "detestable and horrible conspiracy". However, at Walpole's insistence, the Commons resolved to proceed against John Plunket, George Kelly, and Atterbury with bills of pains and penalties, rather than by trial and execution. (Oxford DNB, Wikipedia s.v. Atterbury, State Trials p.382)
A bill of pains and penalties inflicts a punishment, less than death, upon a person supposed to be guilty of high offences such as treason and felony, without any conviction in the ordinary course of judicial proceedings, being different from a bill of attainder in that the punishment inflicted by the latter is death (Legal Dictionary). Although the defending counsel argued that bills of pains and penalties and bills of attainder were inconsistent with the constitution and the only few instances were later condemned, the counsel for the bill pointed out that some of the regicides were punished by bills of pains and penalties (State Trials p.443).
Receiving the Report of the Commons as well as related letters and papers, the House of Lords set up a committee on 16 March, who made their Report on 23 April. The Committee confirmed the deciphering contained in the Report of the Commons.
The Lords accepted the Report on 24 April (State Trials p.390).
In the meantime, the Commons successively passed bills of pains and penalties against John Plunket, George Kelly, and Atterbury and delivered them to the Lords. After passing the bills against Plunket (State Trials p.390; Lords Journal, 29 April) and Kelly (State Trials p.397; Lord Journal, 3 May), the second reading of the bill against Atterbury was held on 6 May in the Lords.
During the proceedings, there were some discussions about disclosure of the deciphering activities.
On 6 May, when Edward Willes admitted that he did use a key in deciphering letters offered in evidence by the counsel for the bill, Atterbury and his counsel insisted that Willes should produce the key, the request was rejected. (Lords Journal, 6 May) On 7 May, when one Peter Thouvois attested that the copies of the three letters of 20 April 1722 were true copies, except such words as were written over figures, Atterbury asked if he had any express warrant under the hand of one of the principal secretaries of state for opening the said letter, it was resolved "That it is the Opinion of this House, That it is inconsistent with the public Safety, as well as unnecessary for the Prisoner's Defence, to suffer any further Inquiry to be made, upon this Occasion, into the Warrants which have been granted by the Secretaries of State, for the stopping and opening Letters which should come or go by the Post, or into the Methods that have been taken by the proper Officers at the Post-office in Obedience to such Warrants."
Edward Willes was then examined and testified upon oath to the truth of deciphering of the three letters dated 20 April 1722. (Two decipherers were involved in deciphering these letters. On 1 May, the other decipherer Anthony Corbiere testified in proceedings against George Kelly (Lords Journal).)
When Atterbury asked "Whether it is possible to declare certainly, that any Number stands for a Name beginning with any particular Letter, unless the immediate preceding and immediate subsequent Number appears to denote a Name, or Words, beginning with the same Letter", Willes expressed unwillingness to answer, declaring "That it would tend to the Discovery of his Art, and to instruct ill-designing Men to contrive more difficult Cyphers." The Lords resolved to drop the question. When Atterbury persisted on putting several questions to Willes relating to the method of deciphering, the Lords resolved "That it is the Opinion of this House, that it is not consistent with the public Safety, to ask the Decypherers any Questions, which may tend to discover the Art or Mystery of Decyphering."
(The above question of Atterbury may be a strategy formed with the advice of John Davys. Davys thought blanks in the deciphered letters published in the Commons Report provided a basis for objection. It was considered that the decipherer might be in some distress if he were urged to explain how he could be assured of the initial letters of two or three unknown words and yet be wholly in the dark as to the initial letters of several others (Davys p.38-39).)
Willes attested that the cipher in George Kelly's hand (F.11) was part of the cipher in which the letters of 20 April 1722 were written. (Lords Journal, 8 May)
Atterbury desired of the House that he might have copies of the three deciphered letters in order to see if they were truly decyphered. For once, his request was granted and it was ordered that Atterbury have copies of the three deciphered letters, with the deciphering interlined, to be delivered to him forthwith; and that the said copies be made by one of the clerks of this house, in the presence of the solicitor for the bill, and under the inspection of one of the decipherers.
On 9 May, strenuous defense of Atterbury was made by his counsel, which Lords Journal simply records "Sir Constantine Phipps and Mr. Wynne were heard, in Behalf of the Bishop of Rochester" but which are reproduced in State Trials (pp.398-406 and pp.406-429).
Phipps questioned the deciphering as follows (State Trials p.401).
After all, Atterbury's counsel dropped the issue of truth of deciphering, saying on 11 May "That they should not trouble their Lordships touching the Decyphering the Three Letters of the 20th of April, 1722, whereof they had had Copies." (Lords Journal) Later, Atterbury complained of their "allowing me Copies of the Decypher'd Letters, tho petition'd for, till the Trial was so far advanced, and I so employed and weakned by it, that I had not sufficient time to consider them (State Trials, p.435).
Even after the issue of deciphering was dropped, identity of the persons represented by pseudonyms (fictitious names, feigned names) was another matter. Atterbury's counsel strenuously denied that Jones, Illington, and 1387 referred to Atterbury.
First, identification of the recipients are explained as follows in the Report.
More controversial than these was the attribution of the pseudonyms Jones, Illington, and 1378 to Atterbury. According to the Report, deciphering indicates the code 1378 represents a name of a person beginning with R (i.e., Rochester). Further, their content indicated that the three letters were written (or dictated) by the same person. Further, the situations mentioned in the letters match those of Atterbury at the time. That is, the writer speaks himself of being in ill health, in great pain, under some sad and melancholy circumstances, which made him uncapable of doing anything regularly at that time, but which he expected would soon blow over, while Atterbury's wife was ill and died six days after and he himself was afflicted with gout.
Further, the three letters were written in George Kelly's handwriting and there was a testimony that Kelly said he was employed in writing letters for Atterbury to the Pretender's agents abroad; that Atterbury never let him carry a bit of his handwriting out of the room; and that Kelly use both a numerical cipher and a cipher of fictitious names.
From such evidence, the Report concluded that the letters were dictated by Atterbury to Kelly and "Jones", "Illington", and "1378" all referred to Atterbury. (State Trials, p.361-362).
Despite the defending counsel's counterarguments, the bill of pains and penalties for Atterbury was passed on 15 May 1723.
The above cipher, used in the three letters said to be dictated by Atterbury, was also used in letters from Spain to Dumville (whose identity was not revealed) and an enclosure considered to be from the Duke of Ormonde to some person abroad whose name begins with L. These were about a planned expedition of the Duke of Ormonde (residing in Spain) to land in England with arms. (State Trials, p.338-340)
The same cipher is also used in letters from George Kelly and to Dennis Kelly.
The Report of the House of Commons printed relevant documents in the Appendix under sections A-K:
A Foreign Correspondence (p.146)
AA Papers relating to Captain Halstead (p.163)
B Papers relating to Christopher Layer (p.172)
BB Papers relating to an intended Invasion (p.214)
C Papers relating to John Plunket (p.218)
D Papers relating to the Bishop of Rochester (p.244)
E Papers relating to George Kelly (p.261)
F Papers relating to Dennis Kelly (p.299)
G Papers relating to John Sample (p.311)
H Papers relating to the Duke of Norfolk and others (p.319)
I Papers relating to Scotland (p.335)
K Papers relating to Ireland (p.347)
These papers include some cipher materials.
Section 21 under B, including No. 1 to No. 42, is a larger bundle of papers belonging to Christopher Layer, another conspirator. The first of this bundle, B.Y. 1, is a list of code names for over 300 names and common words:
A cipher table is attached:
a b c d e f g h i k l m n o p q r s t u w x y [z]
o p q r s t u w x y z a b c d e f g h i k l m [n]
This is a short list of code names. Layer said he received these names from Plunket (State Trials, p.350).
Italics, by the present author, indicates which is the fictitious name.
An expression "Burford's Club" is often used in Plunket's letter to Dillon (State Trials, p.350). Names Digby and Rogers are often mentioned (State Trials, p.353 etc.).
This is a list of code names for 24 people. It is called the Duke of Bewrick's Key in a letter signed "N. Wogan" (State Trials, p.353).
|K. James||Mr. Kerry|
|D. Berwick||Mt. Dumont|
|K. George||Mr. Atkins|
|The Prince||Mr. Aldsworth|
|D. Marlborough||Mr. Eyrs|
|Lord Sunderland||Mr. Dunbar|
|Lord Stanhope||Mr. French|
|Mr. Dillon||Mr. Drycot|
|Mr. Plunket||Mr. Reyley|
|Mr. Wogan||Mr. Henley|
|The Parliament||Mr. Hall|
|The Regent||Mr. Ferrard|
|The Congress||The Company|
|The Regency of England||Mr. Fellows|
While a letter of the Duke of Berwick to Plunket, dated 6 April 1714, writes "I have received Yesterday your's with a Cypher," the above cipher is different from this in view of the entries "K. George" and "The Regent."
George I succeeded to the British throne in August 1714 and the Duke of Marlborough died in June 1722. France was under Regency from 1715 to 1723. Regency in England was discussed in relation to the King's occasional absence in Hanover.
This is a list, in Plunket's handwriting, of code names for more than 100 people and common words.
This cipher was used in a letter from Rogers [Plunket] to Digby [Dillon] dated 23 July 1722 (C.62) and several others (State Trials, p.350). This cipher was employed to identify the addressees Chevers and Jackson (see above) and pseudonyms used in other letters (State Trials, p.352, 353, 363, 444, etc.). The defending counsel questioned the applicability of Plunket's cipher in letters written by Kelly, purportedly dictated by Atterbury (State Trials, p.437), which was countered by an argument that the cipher was used in Kelly's correspondence (State Trials, p.444).
This is a list of code names for about 200 names and words, including verbs . Names beginning with A are always represented by pseudonyms beginning with B and vice versa (This nature is used in State Trials, p.338).
|Bing, Sir Geo.||Asburn|
|to Invade||Know, Kiss|
|Mar, Lord||Lane, Layburne|
The Commons Committee made the following observations about this cipher (State Trials, p.353).
This is a supplement to the cipher used in the three letters of 20 April 1722 attributed to Atterbury (see above). It includes a list of code names for 23 people and numerical codes: 72 (arrangement), ..., 1804 (we).
Appendix H includes papers relating to the Duke of Norfolk and others, among which H.34-H.37 are numerical codes for Mr. Burton. According to the Report, the Duke of Norfolk, among others, was concerned in the treasonable correspondence conveyed through the hands of Mrs. Spelman, to whom several letters from abroad were directed by the name of Mr. or Mrs. Burton (State Trials, p.378).
This cipher distinguishes slashed digits from those without a slash. Thus, while 21-24 designate l, k, j, h, the same digits with a slash designate o, p, q, r.
This cipher is designed for French, in view of lack of "w" in the cipher alphabet and the vocabulary of the codes. It distinguishes slashed digits from those without a slash. Thus, while 31-35 designate ba, be, bi, bo, bu, the same digits with a slash designate ca, ce, ci, co, cu.
This cipher was marked D, O, and J and was probably between George Jernegan, a Jacobite, and the Duke of Ormonde (State Trials, p.378).
After this, for each letter of the alphabet, several words are listed with numbers: for A, 1 (Accommodement), 2 (Anglois), ..., 13 (Assemblee); for U, 1 (Vaisseau), 2 (Venise), 3 (Vienne), 4 (Vicomte de), 5 (Viceroy), 6 (Victoire), 7 (Union), 9 (Voyage).
This cipher includes substantially the same cipher alphabet as the above image for H.35, with some corrections and omissions. Further, code numbers and nulls as shown below are attached.
This cipher was marked "A Key and Cipher, with Mr. Farmer and Jery" and was probably a cipher between the Pretender and Jernegan (State Trials, p.378).
This is a list similar to the one attached to the cipher of H.35 but in English vocabulary. For each letter of the alphabet, several words are listed with numbers: for A, 1 (Army), 2 (Alliance), ..., 7 (Assemblee); for B, 1 (King of England), 2 (of France), 3 (of Spain), etc. Unlike H.35, the arrangement disregard of the initial letters provides a better security (supposing the list is meant to be a code with combinations such as "A1", "A2", etc.).
Reports from Committees of the House of Commons, Vol. 1 (1803) (Google, another scan at Google)
A Complete Collection of State Trials, Vol. 6 (1730) (Google), another edition: Vol. 16 (1816) (Google)
The Historical Register: containing an impartial relation of all transactions ..., Vol. 9 (Google)
Lords Journal (British History Online)
'Atterbury, Francis' in Oxford DNB
John Davys, An Essay on the Art of Decyphering (1737)
Cambridge University Library (2010), 'The Atterbury Plot' in Under Covers: Documenting Spies (online)... Reproduces an image of a letter in cipher.