Stratford Canning, notwithstanding that his task seemed almost hopeless, remained some four months in the Spanish capital. So long as Cea Bermúdez was in power it was plainly useless to expect that Ferdinand could be induced to enter into the views of the British government. Canning, accordingly, set himself to work to undermine the position of that minister. For a brief moment he seems to have been sanguine that, by means of "a difference of opinion in the Cabinet," he might be able to effect his purpose. But his hopes were speedily dispelled. The three ministers opposed to Cea Bermúdez with whom he had established communication were suddenly dismissed by the King.[328] Nor was he more fortunate with Queen Christina, with whom he contrived "to open a direct and confidential intercourse."[329] She appeared to agree with him that the triumph of Dom Miguel in Portugal could not fail to react disastrously upon the fortunes of her daughter, but she either could not, or would not influence the King to regard matters in the same light. Sir Stratford's difficulties had been aggravated by the news that Dom Pedro's resources were exhausted, and that his position at Oporto was desperate. But a few weeks after Canning's departure from Madrid the situation in Portugal assumed a very different complexion. Sartorius, the admiral of the constitutional fleet, had been replaced by Charles Napier, who from the first appears to have judged the political and strategical situation correctly. The mere possession of Oporto and victorious sallies against the Miguelite lines would never, he saw clearly, win the crown for Donna Maria. A bold move on Lisbon itself could alone give the victory to the constitutionalists. The capital, in his opinion, might be captured, provided he could obtain the command of the sea. Having succeeded in persuading Dom Pedro and his advisers to adopt his views, he sought out the Miguelite fleet, and, on July 5, 1833, despite the inferiority of his ships, completely destroyed it off Cape St. Vincent.[330] Three weeks later, Lisbon was occupied by Terceira, the constitutional general, in the name of Donna Maria.