JOHN SHEFFIELD, DUKE OF BUCKINGHAMSHIRE (1649-1721) was associated in his latter days with the wits and poets of the reign of Queen Anne, but he properly belongs to the previous age. He went with Prince Rupert against the Dutch, and was afterwards colonel of a regiment of foot. In order to learn the art of war under Marshall Turenne, he made a campaign in the French service. The literary taste of Sheffield was never neglected amidst the din of arms, and he made himself an accomplished scholar. He was a member of the privy council of James II., but acquiesced in the Revolution, and was afterwards a member of the cabinet council of William and Mary, with a pension of £3000. Sheffield is said to have "made love" to Queen Anne when they were both young, and her majesty heaped honours on the favourite immediately on her accession to the throne. He was an opponent of the court of George I., and continued actively engaged in public affairs till his death. Sheffield wrote several poems and copies of verses. Among the former is an Essay on Satire, which Dryden is reported to have revised. His principal work, however, is his Essay on Poetry, which received the praises of Roscommon, Dryden, and Pope. It is written in the heroic couplet, and seems to have suggested Pope's "Essay on Criticism." It is of the style of Denham and Roscommon, plain, perspicuous, and sensible, but contains as little true poetry, or less, than any of Dryden's prose essays.