Duke was purchased from a Mr Charles Wyndham on 22 June 1739, for the sum of £697.8.7d paid for the hull and £106.18.8¼d for the stores.

The fireship Duke was fitted out at Woolwich Dockyard between 7 July and 12 August 1739, for a further sum of £1,832.9.11d, and was commissioned in June that year under Commander Savage Mostyn.

In March 1740 she came under Commander William Russell, serving with Chaloner Ogle's squadron.

Duke was expended at St Tropez on 14 June 1742 in an operation that saw the successful destruction of five Spanish galleasses.

[2] It was recorded that Duke "had the good fortune to destroy so many at the expense of one fireship; a vessel perhaps the best expended that ever was burnt, considering the importance of these galleys to the enemy, and the difficulty of getting more soon enough for their purpose at so critical a juncture, when they stood most in need of them: But, indeed, the Spaniards indiscreetly mooring alongside of one another, contributed to the destruction of them in so easy a manner; though this observation is not made to diminish so glorious and well-executed a piece of service, which is worthy of the greatest applause...'[2]