plate fleet. On 30 Sept. he was joined by Captain Charles Holmes [q. v.] in the Lennox, with the news that he had been chased the day before by a squadron of seven Spanish ships. These came in sight the next morning (1 Oct.) in the southern quarter. When first seen, the Spaniards were straggling in two divisions. By closing with them at once, and before they could get into compact order, Knowles thought that he would risk losing the weather-gage, without which—according to the Fighting Instructions—no attack would be possible. He accordingly spent some time in working to windward, and when at last he steered for the enemy, the unequal sailing of his ships disordered his line, and rendered the attack ineffective. The leading ships, too, misunderstood or disobeyed the signal to engage more closely, and took little part in the action. The brunt of it fell on the Strafford, commanded by Captain David Brodie [q. v.], and on Knowles's flagship, the Cornwall, which, owing to the disordered state of the line, was singly opposed to three of the enemy's ships, and sustained severe damage. She did, however, beat the Africa, the enemy's flagship, out of the line; the Conquistador struck to the Strafford, and the Canterbury, which had been delayed by the bad sailing of the Warwick, coming up, the Spaniards took to flight. It was then just dark. Knowles made the signal for a general chase; but the Cornwall had lost her main topmast and was disabled, and as the Conquistador just then rehoisted her flag and endeavoured to escape, Knowles contented himself with compelling her to strike again and with taking possession of her. In the pursuit the Africa was driven on shore by the Strafford and the Canterbury, and was afterwards burnt. The other Spanish ships escaped.
In writing of the engagement to Anson, Knowles spoke of the ‘bashfulness—to give it no harsher term,’ of some of the captains; and he publicly animadverted on the conduct of Captain Powlett of the Tilbury, the leading ship. Powlett applied for a court-martial, which was granted; but he was afterwards allowed to withdraw his application. When, however, it was openly said on board the Cornwall, the Strafford, and the Canterbury that the captains of the other four ships had been ‘shy,’ they retaliated by officially accusing the admiral of having given ‘great advantage to the enemy by engaging in a straggling line and late in the day, when he might have attacked much earlier;’ of having ‘kept his majesty's flag out of action;’ and of having ‘transmitted a false and injurious account’ to the admiralty. A court-martial on Knowles was accordingly ordered, and sat at Deptford in December 1749. Captain Innes of the Warwick acted as prosecutor, in the name of the four captains. The trial, based exclusively on points of seamanship and tactics, was necessarily extremely technical. The court decided that Knowles was in fault in taking his fleet into action in such a straggling line, and also in not going on board another ship and leading the chase in person. He was sentenced to be reprimanded. The four captains who had acted as prosecutors were then put on their trial. Holmes of the Lennox was honourably acquitted; but Powlett and Toll, who had commanded the two leading ships, were reprimanded, and Innes was suspended for three months. Many duels followed. After the trials Knowles, who received four challenges, interchanged shots with Holmes on 24 Feb. A meeting took place between Innes and Clarke, the captain of the Canterbury, the principal witness against him, on 12 March 1749–50, and Innes was mortally wounded. Several more duels were pending, when the king not only forbade them, but ordered the challengers into custody (Gent. Mag. xx. 22, 137).
In 1752 Knowles was appointed governor of Jamaica, and held the office for nearly four years. He offended the residents by insisting on the supreme jurisdiction of the English parliament, and by moving the seat of government to Kingston, thus causing a depreciation of property in Spanish Town. A petition for his removal, signed by nineteen members of the assembly, was presented to the king, and charges of ‘illegal, cruel, and arbitrary acts’ were laid before the House of Commons. After examination by a committee of the whole house, the action of the assembly of Jamaica was condemned as ‘derogatory to the rights of the crown and people of Great Britain,’ and Knowles's conduct, by implication, fully justified. But Knowles had already returned to England and resigned the governorship, January 1756.
On 4 Feb. 1755 he had been promoted to be vice-admiral, and in 1757, with his flag in the Neptune, was second in command under Sir Edward (afterwards Lord) Hawke [q. v.] in the abortive expedition against Rochefort. On the return of the fleet public indignation ran very high, and though for the most part levelled against the government and Sir John Mordaunt (1697–1780) [q. v.], Knowles was also bitterly reproached. He published a pamphlet entitled ‘The Conduct of Admiral Knowles on the late Expedition set in a true light;’ but this met with scant favour, and a notice of it in the ‘Critical Review’ (May 1758, v. 438) so far exceeded