The Man Who Broke Napoleon's Codes (32 page)

Marching to Almaraz had taken two days, and moving to the assault position a couple of hours, but the Highlanders' rush under the guns of the fort was over in minutes. The French were able to fire once or twice before they could hear the shouting of British soldiers just a few feet away at the base of their ramparts. Heavy stones and grenades were hurled over the parapet. Not for the first time, the stormers found an unexpected problem at this most critical juncture. Their ladders were too short. After a few moments, however, they found a way of lashing them together in pairs and soon were mounting their steps and pouring into the fort.

Seeing the British success, the French on the other side of the bridge turned their ordnance on Fort Napoleon, trying to dislodge the British from their new prize. The French cannon fire failed to turn the tide, however, and General Hill's troops soon set about destroying the pontoon bridge, torching supplies and breaking up the rest of the stores that the French had gathered there. Most of the defenders, despite Daddy Hill's earlier order, were able to flee into the surrounding hills.

The British would have lingered around the Tagus longer to achieve the secondary objective of destroying stores around the crossing point, but an alarm spread by Major General Lumley, the cavalry screen commander, led them to pull back quickly. Still, Wellington's main task had been performed: any attempt by Soult or Marmont to reinforce one another would now take one week or even ten days longer.

News of the Almaraz operation was greeted with satisfaction in Fuente Guinaldo. The perfectionist Wellington dwelt long on Major General Lumley's panic, “taking alarm at the least movement of the enemy.” But Hill, the only man Wellington would place his trust in on an independent mission of that kind, had shown himself worthy of that distinction once more. The news of Almaraz and the general appreciation that some great project was about to be launched created an air of expectation about the headquarters. The comings and goings of messengers and ADCs reached a new level of intensity, and conversation around the commander's table each evening was decidedly animated.

There was so much of import to discuss, after all. The prime minister, Spencer Perceval, had been assassinated in the House of Commons, prompting vivid speculation that the killing might be the work of Radicals or even French agents, until it turned out that the assassin was an insane bankrupt. Nevertheless, this violent act produced a great deal of maneuvering by two of Lord Wellington's correspondents, his brother Lord Wellesley and the secretary of war, Earl Liverpool, to see if they could form a new government. Having been born and bred to this kind of Tory intrigue, Wellington, behind his customary mask of inscrutibility, awaited the outcome of this new campaign at Westminster just as keenly as he did that of Napoleon's expedition to Russia.

Napoleon's Polish war (for the emperor referred to it as such, scarcely imagining he would have to go as far as Russia itself) was an altogether safer topic for table talk than London politics. Major Cocks, who had dropped in for dinner before setting off for Lisbon, felt that the Russians would be able to draw the French deep into their country and do them all sorts of mischief. D'Urban believed the emperor intended “amid the blaze of a successful Russian war to throw the Peninsula and his defeats there into the shade.” Wellington, of course, would have had the last word in
these ruminations and his view was that whatever the outcome of the eastern campaign, it had precipitated a weakening of forces in Spain, a situation that was to his advantage but could not go on forever. His thinking in 1809, prior to Talavera, had been similar, but this time he had far better intelligence about the numbers and movements of French forces—in particular the withdrawal of two divisions of Imperial Guard from northern Spain, which had left the Army of the North running from one rebellious conflagration to another. This disorder was once again requiring some of Marmont's troops to move up northward, weakening his central deployment in the plains around Salamanca.

More and more it seemed to Wellington that Marmont should be the target of his next operation. There were one or two months in which to take advantage of the fresh fodder in the fields and the drier weather. An attack on Marmont, if successful, would eventually force an evacuation of Andalucia. If he struck Soult first, though, the Army of Portugal might either move down to help him or just remain where it was, keeping its communications with Madrid and France open. On 26 May Wellington sat at his desk in Fuente Guinaldo and drew all of these arguments together in a letter to the secretary of war, which concluded: “I propose, therefore, as soon as ever the magazines of the army are brought forward … to endeavor, if possible, to bring Marmont to a general action … I am of the opinion also that I shall have the advantage in the action, and that this is the period of all others in which such a measure should be tried.” This was a momentous decision. It marked the first time since his return to Portugal three years before that Wellington was going to try his hand at an offensive battle. Waiting for the enemy to come to him, at Talavera, Busaco or Fuentes de Oñoro, had worked very well, because it had always allowed him to choose the ground, a judgment of which he was the master.

There was another reason for striking the Army of Portugal first, and it was based on the information gleaned from intercepted correspondence. A further package of captured letters, dated 1 May, had revealed much about the relations between the senior French commanders. Whoever had prepared these dispatches was guilty of an unpardonable lapse in security. In a letter to Dorsenne, the king's secretary had included a copy of another missive from Marmont to Madrid in April—a copy, however, that was entirely
en clair.
Scovell must have
treated the arrival of every subsequent messenger in Guinaldo's little plaza with nervous excitement. Had some guerrilla commander intercepted and sent in an original of that same letter, one in cipher, then the French higher command code would have been blown apart. Unfortunately for Scovell, who was devoting long hours to deciphering, the original never appeared. The cipher therefore remained a puzzle to which he could only find a partial solution.

The
en clair
copy of Marmont's letter did however provide a vital insight into the row that had broken out between Joseph and Dorsenne after Napoleon transferred the command of his armies. Dorsenne was refusing to cooperate with any orders coming from Madrid. Whether by oversight or by some game of
divide et impera
*
Berthier's instructions to the two men had been different. The notice of the transfer of command sent to Joseph had included Dorsenne and his Army of the North, but the general himself had received no such order. Indeed, Napoleon's note to Berthier prompting the change had not mentioned Dorsenne.

This new information would have helped Scovell in opening up much further Dorsenne's sloppily ciphered letter of 16 April. Looking again at its second paragraph:

Looking at the first sentence, early work already suggested two of the codes:

Reading the 1 May dispatches, it became fairly obvious that 1207 was Berthier, 1264 the emperor and 1328 seemed to be Joseph. It could then be deduced that 1327 and 1333 were Soult and Marmont's armies (although not which was which: that 1333 was the Army of Portugal became apparent when looking at some of Marmont's letters). The phrase “but was making 1165.1060.1238.820,” then appears to be something like “but was making an exception of the Army of the North.”

The uncoded copy of Marmont's April letter may not have turned up in its ciphered form, but the others in the 1 May packet reproduced some of its phrases, since some dealt with the same business. The commander of the Army of Portugal had evidently asked Dorsenne to send a division to Valladolid in support of his operations. In a partially encoded 1 May letter from Jourdan to Marmont, the chief of staff in Madrid noted: “The General has just replied to me that this army is not under the King's orders; HM cannot, as you ask, order General Count Dorsenne 13.577.264.90.1282.544.118.1045.514.2.1202.” Insert the meanings of 2 and 13 and it reads: “… order General Count Dorsenne to 577.264.90.1282.544.118.1045.514 to 1202.” In this scheme, 1202, it becomes clear, is Valladolid, 577 is likely to mean
order
or
send
and so on.

The impact of each of these discoveries became magnified when transferred to other contexts in different messages. By the end of May 1812 Scovell was beginning to get a real toehold on the slippery precipice of the code. As he worked away on the letters, Scovell jotted his hypotheses on scraps of paper—envelopes, official forms, whatever came to hand. He drew up a table about two feet wide and eighteen inches high, marked in columns of one hundred numbers, much like the deciphering tables issued to the French marshals themselves. When he had some confidence in the value of a number, it migrated from the bits of paper to his table.

As Major Scovell tried to attack the Paris Cipher, he was still expected to fulfill his other duties as commander of the Guides and as an AQMG on the staff. Wellington might have been most anxious to receive the key, but it was not a reason to upset the regularity of the
quarter master general's department and the smooth running of headquarters. Code breaking was therefore an activity that he had to pursue in spare moments, often by candlelight in his billet in Guinaldo. Bit by bit, though, he was building up the numbers on his table, scrawling them with his scratchy quill. Sometimes, when he saw a hypothesis handsomely confirmed, he would have the satisfaction of underlining the word on his table. This precious piece of paper was folded into his Conradus notebook and kept about his person. And yet, it was still too early to celebrate the breaking of Joseph's code. Although there were scores of entries on Scovell's chart, there was still a great deal of the cipher that remained obscured to him.

These gaps in Scovell's knowledge of the cipher perplexed Wellington. After all, the Army of Portugal codes had been broken in a couple of days. A few good discoveries had usually sufficed to prize the whole thing apart. Yet here was Scovell, still plodding away with more than a dozen specimens of the Great Paris Cipher, unable to provide the key. With the army preparing to march on Marmont, Wellington was impatient; it was imperative that progress be made quickly.

What else could be done? The Spanish had some decipherers at Cadiz, Wellington knew that. There was also the little office in London, off Abchurch Street, where the foreign secretary and prime minister retained a few fellows skilled in the black arts of secret writing. But sending a dispatch to England or Cadiz would take time; heaven knows when it might come back. There was risk, too, for some minister might boast of the discovery and it would end up in the newspapers. Similarly, if the key were intercepted on its return journey by some French privateer, word would soon get back to Madrid and the whole labor of deciphering would be rendered pointless. There were definitely advantages to keeping this work in his own headquarters. He would allow Scovell more time, but his patience had its limits.

In Salamanca, Marmont was learning of Wellington's preparations through his own network of spies. The bringing forward of magazines announced in Wellington's letter to London was becoming visible to the muleteers and intinerant lemonade sellers who journeyed back and forth across the frontier. Great Portuguese mule trains were coming up from
Guarda toward Vila Formosa on the border. Some British battalions were also in motion. On 1 June, Marmont wrote to Jourdan, “Lord Wellington remains at Fuente Guinaldo and the stores he has gathered there are building up in an incredible fashion. It seems certain that the campaign will begin here in ten days and that the enemy will march on Salamanca.”

The marshal's intelligence, in both its senses, was most acute. He and Wellington were beginning to understand one another and the potentially decisive nature of the contest that was about to start. Just to make sure that his adversary appreciated this all, Marmont resorted once more to his expedient of leaving those words about Wellington's intentions
en clair.
His message got through, for Marmont followed usual procedures and sent duplicates. One messenger was detained by guerrillas and in less than a week the British general had read it and was soon telling London about his opponent's good judgment.

In Madrid, Joseph and his chief of staff awaited events with a sense of enraged impotence. Jourdan had drawn up a memorandum at the end of May outlining what needed to be done in order to defend French interests in Spain. The document showed that Jourdan remained a sound strategist, even if he had long forfeited the emperor's respect. It went through the different armies under the king's command, noting their poor state and the recalcitrance of their commanders before concluding, “The Imperial armies can undertake nothing other than the occupation of the conquered provinces: one can also see that if Lord Wellington … falls on the Army of the South or of Portugal, the army under attack will not be in a state to resist him. “Jourdan could see that after the destruction of the Almaraz bridge, these two armies could do little to help one another rapidly. The answer, the king's adviser believed, lay in the creation of a powerful central reserve under his own hand that could move to assist either army on the frontier and help defend the capital itself. This clear-sighted blueprint was sent to the minister of war in Paris, who showed his own powerlessness and intellectual timidity by replying with a restatement of the emperor's beliefs that no territory should be relinquished, that the French should maintain “an imposing attitude” toward Wellington (an empty piece of imperial
bragadoccio
if ever there was one) and that the forces at Joseph's disposal allowed him to do whatever the situation demanded.