Convened at Portsmouth on 26 July 1809, the members of the court were deliberately chosen by Mulgrave to favour Gambier, and over the next eight days a call was issued for particular witnesses who largely discredited Cochrane with misleading evidence.
Despite popular support, Cochrane's resistance had alienated much of the naval and political establishment in Britain and not long afterwards he was implicated in the Great Stock Exchange Fraud of 1814, convicted and publicly humiliated.
Placing him in command would mean by-passing a number of more senior officers, inevitably causing offense, while his status as a Radical Member of Parliament for Westminster made him an outspoken opponent of Prime Minister Lord Portland.
[7] Cochrane initially refused the offer, but was later directly ordered to prepare and lead the operation, sailing to join Gambier in his ship, the frigate HMS Imperieuse.
[13] Gambier then ordered the reinforcements to withdraw, leaving Cochrane again unsupported against the rest of the main French fleet which was gradually dragging itself off the shoals and into the relative safety of the Charente River.
Despite a letter from Gambier suggesting he withdraw, Cochrane renewed his attack on 13 April but was unable to cause any significant damage to the French ships as they threw stores and guns overboard to facilitate their escape.
[19] He concluded by praising both Rear-Admiral Robert Stopford or Captain Sir Harry Neale, neither of whom took part in the fighting, stating that "handsome and earnest Manner in which both these meritorious Officers had volunteered their Services .
He was lauded as the hero of the action and awarded membership of the prestigious Order of the Bath on 26 April, almost immediately after his return,[21] but concern was already being expressed both within the Navy and in the press about the failure of the fleet to secure a greater victory over a vulnerable and panicked French force; an editorial in The Times attacked Gambier for hesitation.
[23] Cochrane was unmoved, and refused to back down when Mulgrave first threatened him with the government's displeasure and then offered him a frigate squadron and infantry regiment of his own to conduct operations against the French as he wished without oversight should he drop the complaint.
[20] Mulgrave immediately notified Gambier of Cochrane's intentions and the admiral, aware that his competence and bravery were being called directly into question, demanded a court-martial to investigate his conduct.
[25] When Cochrane was asked in advance of the trial to provide written specifics of his accusations against Gambier he refused on the grounds that it would be insubordinate, leaving the court-martial to set the terms of the charges.
[30] By stacking the court with senior officers, Cochrane's opponents had ensured that those called to give evidence, whose careers relied on recommendations from men like those in the room, would not be free to express their honest opinions without risking their future advancement.
[33] It was also ensured that the charts of the action placed before the court were prepared by senior warrant officers Thomas Stokes and Edward Fairfax of Gambier's flagship HMS Caledonia.
Fairfax had seen action in the initial night attack, but neither officer had spent significant time in Aix Roads, or made their own soundings; their plans were based on captured French charts.
These charts were revealed to greatly exaggerate the navigational hazards and defences of Basque Roads, including rendering the channel as half its actual width and most particularly depicting a large and dangerous shoal blocking the entrance to the anchorage that did not exist.
A second packet of documents was also issued, which included additional correspondence and a report on the defences of Basque Roads from April 1807 by Commodore Richard Goodwin Keats, explaining his decision not to attack a French squadron anchored there at that time.
[35] They were followed by John Spurling, Master of HMS Imperieuse, who was closely questioned on his ability to reliably document signals in the midst of battle; he acknowledged that he had been unable to retain a complete record.
[45] He mentioned his assumption that Gambier paused so that the crews could eat lunch, stating, "I could not in any other way account for a proceeding, that thus enabled the helpless French ships to endeavour their escape".
[48] Cochrane then read out a letter sent to him by Gambier on the morning of 13 April, when much of the French fleet was still exposed, which urged him to withdraw, lest he "tarnish [the victory] by attempting impossibilities".
Stopford fully supported Gambier's case and took full responsibility for withdrawing the squadron sent to reinforce Cochrane on 12 April during the following morning, citing the dangers of the anchorage, on which his own ship had grounded in the night.
Bligh was called again on the morning of 1 August, testifying that he had overheard Cochrane stating that if Gambier had led the fleet into the anchorage on 12 April, three of four British ships might have been lost.
Beresford described Cochrane's signals on the day of the battle as "very improper" and "impossible",[73] and reiterated Gambier's concern that he may have suffered heavy losses had he attacked Aix Roads with his fleet.
[75] Samuel Raven was recalled and cross-examined as to the locations of the stranded French ships in Aix Roads, followed by Captain Stair Douglas of HMS Bellona, who stated of Gambier that "I do not know of any neglect whatever" in his conduct.
This evidence was halted by Curtis, who gently admonished Gambier for asking directly whether Cochrane had discussed the admiral's "conduct or misconduct" with any officers on board Caledonia.
[81] Sir Harry Neale, Gambier's flag captain, was called first and recounted Cochrane's distrust of the official Neptune François maps used by the fleet in planning the action.
Seymour was the first officer other than Cochrane to offer criticism of Gambier's conduct, stating that reinforcements could have been sent into Aix Roads at 11:00 on 12 April, some three hours earlier than the time of their eventual deployment.
[84] Captain Francis Newcombe of the brig HMS Beagle was next called, and complained about Cochrane's conduct, the latter having fired shot in the direction of his vessels during the battle as a means of encouraging him to engage the enemy more closely.
[94] The effect in the Navy however was quite the opposite; Admiral James Bowen wrote "It will be a lesson to restless and inexperienced young officers not to hazard a mischievous opinion", and Lord Collingwood, a patron of Cochrane, hoped that the verdict would free him of bad influences.
[95] Cochrane was "to all intents and purposes, officially disgraced";[94] he later wrote that the effect was that "From this time forward I never trod the deck of a British ship of war at sea, as her commander, till thirty-nine years afterwards".
William James noted in 1827 that "we cannot refrain from observing, that several of members, particularly the president (Sir Roger Curtis) and Admiral Young, evinced a strong bias in favour of the accused".